Final Interchange Justification Report

Transcription

1 I- / TROSPER ROAD Final Interchange Justification Report Prepared for: Prepared by:

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7 I-/Trosper Road Final Interchange Justification Report Prepared for City of Tumwater Israel Rd SW, Olympia, WA 0 Prepared by SCJ Alliance 0 Tallon Lane NE Lacey, WA T

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9 I-/Trosper Road Final Interchange Justification Report (IJR) Table of Contents. POLICY POINT NEED FOR ACTION...- INTRODUCTION... - WHAT IS THE PURPOSE OF THE PROJECT?... - WHAT IS THE PURPOSE OF THIS IJR?... - WHAT IS THE STUDY AREA FOR THIS IJR?... - WHAT ARE THE ANALYSIS YEARS... - WHAT DOES THE EXISTING TRANSPORTATION SYSTEM INCLUDE?... - I-/Trosper Road Interchange... - Local Streets... - Project Study Area Intersections... - WHY IS THERE A NEED FOR ACTION?... - HOW WERE TRAFFIC OPERATIONS ANALYZED?... - WHAT ARE CURRENT AND EXPECTED FUTURE NO BUILD TRAFFIC CONDITIONS? Existing Peak Hour Traffic Conditions No Build Peak Hour Traffic Conditions No Build Peak Hour Traffic Conditions... - COULD LOCAL STREET IMPROVEMENTS ADDRESS I- INTERCHANGE CONGESTION? POLICY POINT REASONABLE ALTERNATIVES...- INTRODUCTION... - HOW WERE INITIAL IMPROVEMENT ALTERNATIVES IDENTIFIED?... - Brainstorming of Ideas... - Evaluation of Brainstormed Ideas... - HOW WAS THE SHORTLIST OF ALTERNATIVES DEVELOPED?... - Base Condition /No Build Intersection Capacity Alternatives... - Context Sensitive Intersection Capacity Alternatives... - Traffic Diversion Alternatives... - HOW WAS THE SHORTLIST OF ALTERNATIVES EVALUATED?... - Evaluation Criteria... - Alternatives Analysis... - WHAT WERE THE RESULTS OF STEP ONE SCREENING?... - Scoring of Alternatives by Criteria... - Project Costs... - Value Ranking... I-/Trosper Road Interchange Justification Report i

10 I-/Trosper Road Final Interchange Justification Report (IJR) TABLE OF CONTENTS (CONTINUED) WHAT WERE THE RESULTS OF STEP TWO SCREENING?... - Criteria and Weighting... - Scoring of Alternatives by Criteria... - Project Costs Value Rankings WHAT IMPROVEMENTS ARE RECOMMENDED FOR A BUILD ALTERNATIVE?... - Phasing Analysis... - Phasing Recommendations... - WHAT IMPROVEMENT CONCEPTS WERE CONSIDERED AND REJECTED? POLICY POINT OPERATIONAL AND COLLISION ANALYSES...- INTRODUCTION... - HOW WAS THE TRAFFIC ON I- AND AT INTERSECTIONS ANALYZED?... - WHAT IS THE EXISTING AND PROPOSED SPACING OF INTERCHANGES ALONG THE I- CORRIDOR WITHIN THE STUDY AREA?... - HOW IS EXISTING (0) TRAFFIC OPERATING IN THE STUDY AREA?... - Transportation Performance Measures Interchange Ramp Analysis Intersection Operations Analysis... 0 Lane Utilization... - HOW WERE PEAK HOUR TRAFFIC VOLUMES FORECAST IN THE STUDY AREA?... - Modifications to Existing Regional Travel Demand Model... - Develop and Apply Annualized Traffic Volume Growth Rates... - HOW DO THE PROPOSED ACCESS MODIFICATIONS IMPROVE 0 OPENING YEAR OPERATIONS AT THE I-/TROSPER ROAD INTERCHANGE? Interchange Ramp Analysis AM Peak Hour Intersection Operating Performance Traffic Queuing Analysis Results Lane Utilization... - HOW DO THE PROPOSED ACCESS MODIFICATIONS IMPROVE 00 DESIGN YEAR OPERATIONS AT THE I-/TROSPER ROAD INTERCHANGE? Interchange Ramp Analysis AM Peak Hour Intersection Operating Performance PM Peak Hour Intersection Operating Performance Traffic Queuing Analysis Results Lane Utilization... - I-/Trosper Road Interchange Justification Report ii

11 I-/Trosper Road Final Interchange Justification Report (IJR) TABLE OF CONTENTS (CONTINUED) HOW WOULD THE PROPOSED BUILD ALTERNATIVE AFFECT THE CONNECTIONS WITH LOCAL ROADS AND INTERSECTIONS?... - SUMMARY OF TRAFFIC OPERATIONAL IMPACTS... - WHAT IS THE EXISTING CRASH EXPERIENCE IN THE PROJECT AREA?... - What was the Process used to Evaluate Crashes in the Project Area?... - What is the Existing Crash Experience in the Project Area?... - HOW IS CRASH FREQUENCY EXPECTED TO CHANGE OVER THE PLANNING PERIOD? POLICY POINT # ACCESS CONNECTIONS AND DESIGN...- INTRODUCTION... WILL THE I-/TROSPER ROAD PROJECT PROVIDE A FULLY DIRECTIONAL INTERCHANGE CONNECTED TO PUBLIC ROADS?... What Modifications would be Made to the I- Mainline?... What are the Proposed Trosper Road Interchange Modifications?... HOW DO THE PROPOSED ACCESS REVISIONS FIT INTO THE LARGER CAPITOL BOULEVARD CORRIDOR PLAN PROJECT?... - WILL THE MODIFIED AND NEW INTERCHANGES BE SPACED ACCORDING TO GUIDELINES?... - WILL THE MODIFIED AND NEW INTERCHANGES BE DESIGNED TO PRECLUDE VARIANCES FROM STANDARDS?... - WHAT ARE THE CONCEPTUAL SIGNING PLANS FOR THE NEW OR MODIFIED INTERCHANGES? POLICY POINT # LAND USE AND TRANSPORTATION PLANS...- INTRODUCTION... - ARE THE PROPOSED ACCESS POINT REVISIONS COMPATIBLE WITH LAND USE PLANS FOR THE AREA?... - ARE THE PROPOSED ACCESS REVISIONS CONSISTENT WITH STATE, REGIONAL AND LOCAL TRANSPORTATION PLANS? POLICY POINT # FUTURE INTERCHANGES...- INTRODUCTION... ARE THE PROPOSED ACCESS POINT REVISIONS COMPATIBLE WITH OTHER FUTURE INTERCHANGE IMPROVEMENTS?.... POLICY POINT # - COORDINATION...- INTRODUCTION... - HOW HAVE THE PROPOSED IMPROVEMENTS BEEN COORDINATED WITH OTHER IMPROVEMENT PROJECTS IN THE AREA?... - I-/Trosper Road Interchange Justification Report iii

12 I-/Trosper Road Final Interchange Justification Report (IJR) TABLE OF CONTENTS (CONTINUED) ARE THERE OTHER WSDOT IMPROVEMENTS THAT NEED TO BE COORDINATED?... - ARE THERE OTHER LOCAL IMPROVEMENTS THAT NEED TO BE COORDINATED?... - HOW WERE LOCAL AND STATE AGENCIES INVOLVED?... - HOW WAS THE PUBLIC INVOLVED? POLICY POINT # ENVIRONMENTAL PROCESSES...- INTRODUCTION... - WHAT TYPE OF ENVIRONMENTAL DOCUMENT WILL BE PREPARED FOR THE PROJECT?... - WHAT IS THE NEPA SCHEDULE AND PROCESS FOR APPROVAL?... - LIST OF TABLES Page Table -: Summary of Performance Scores for Shortlisted Alternatives... Table -: Conceptual Level Cost Estimate Summary... Table -: Value Index for Narrowed List of Alternatives... - Table -: Evaluation Summary of Four Final Alternatives... - Table -: Cost Summary for Final Four Alternatives... - Table -: Value Index for Final Alternatives... - Table -: Projected Traffic Operations Failure Year... - Table -: 0 Existing Merge/Diverge Analysis Results... Table -: 0 Existing Peak Hour Intersection Operations... - Table -: 0 Existing Peak Hour Traffic Queuing at Key Locations... - Table -: Projected 0 Merge/Diverge Analysis Results... - Table -: 0 AM Peak Hour Intersection Operations... - Table -: 0 PM Peak Hour Intersection Operations... - Table -: 0 Peak Hour Traffic Queues No Build and Build Alternatives... - Table -: Projected 00 Merge/Diverge Analysis Results Table -: 00 AM Peak Hour Intersection Operations... 0 Table -0: 00 PM Peak Hour Intersection Operations... - Table -: 00 Peak Hour Traffic Queues No Build and Build Alternatives... - I-/Trosper Road Interchange Justification Report iv

13 I-/Trosper Road Final Interchange Justification Report (IJR) TABLE OF CONTENTS (CONTINUED) LIST OF TABLES Page Table -: 0 and 00 Two-way Volume on Local Streets-No Build Alternative vs. Build Alternative- Table -: 00-0 Crashes and Crash Rates by Location... - Table -: 00-0 I-/Trosper Road Interchange Area Crash Severity... - Table -: Annual Predicted Crashes for the I-/Trosper Road Interchange Area... - Table -: Study Area Projects from WSDOT s Highway System Plan... - Table -: Projects from the Thurston Regional Transportation Plan... I-/Trosper Road Interchange Justification Report v

14 I-/Trosper Road Final Interchange Justification Report (IJR) TABLE OF CONTENTS (CONTINUED) LIST OF FIGURES Figure -: IJR Study Area and Adjacent Interchanges... - Figure -: Study Area Intersections... - Figure -: I-/Trosper Road Interchange... - Figure - Study Process to Develop and Evaluate Reasonable Alternatives... - Figure -: Recommended Build Alternative Improvements... - Figure -: I-/Trosper Road and Capitol Boulevard Improvements in the Build Alternative... - Figure -: 0 PM Peak Hour Comparison of Mainline Volumes and Operations... - Figure -: Study Area Intersections with the Build Alternative... - Figure -: I-/Trosper Road Comparison of 0 PM Peak Hour Traffic Queues... - Figure -: 00 PM Peak Hour Comparison of Mainline Volumes and Operations... - Figure -: I-/Trosper Road Comparison of 00 PM Peak Hour Traffic Queues... - Figure -: I-/Trosper Road Interchange Area Crashes by Severity Figure -: I-/Trosper Road Interchange Area Crashes by Type Figure -: I-/Trosper Road Interchange Area Crashes by Contributing Circumstances Figure -. Conceptual Layout for I-/Trosper Northbound Off-ramp and Capitol/Trosper Intersection.. - Figure -. Conceptual Layout of I-/Trosper Road and Capitol Boulevard Improvements in the Build Alternative... - Figure -: Conceptual Signing and Striping Plan for I-/Trosper Road and Capitol Boulevard Improvements... - Figure -: Public Information Materials... - Page I-/Trosper Road Interchange Justification Report vi

15 I-/Trosper Road Final Interchange Justification Report (IJR) TABLE OF CONTENTS (CONTINUED) LIST OF APPENDICES Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F Appendix G Appendix H Appendix I Appendix J Appendix K Appendix L Appendix M Methods and Assumptions Memorandum Traffic Counts 0 Operations and Queuing Analysis Future Traffic Volumes 0 No Build Alternative Operations and Queuing Analysis 00 No Build Alternative Operations and Queuing Analysis Brainstorming Workshop Results Proposed Alternative Analysis Methodology Evaluation of Shortlisted Alternatives Step Two Improvement Alternatives Operational Analysis Results 0 Preferred Alternative Operations and Queuing Analysis 00 Preferred Alternative Operations and Queuing Analysis Crash Analysis I-/Trosper Road Interchange Justification Report vii

16 I-/Trosper Road Final Interchange Justification Report (IJR) ACRONYMS CBCP DCE FHWA GMA HCM HCS HSP HSS IJR ISAT LOS NEPA NHS RCW RTP TRPC WSDOT WTP Capitol Boulevard Corridor Plan Documented Categorical Exclusion Federal Highway Administration Growth Management Act Highway Capacity Manual Highway Capacity Software Highway System Plan Highway of Statewide Significance Interchange Justification Report Intersection/Interchange Safety Analysis Tools Level of Service National Environmental Policy Act National Highway System Revised Code of Washington Regional Transportation Plan Thurston Regional Planning Council Washington State Department of Transportation Washington Transportation Plan I-/Trosper Road Interchange Justification Report ix

17 Policy Point Need for the Access Point Revision. POLICY POINT NEED FOR ACTION 0 0 Introduction In 0, the City of Tumwater and Thurston Regional Planning Council (TRPC) partnered on the Capitol Boulevard Corridor Plan (CBCP) from M Street SE to Tumwater Boulevard SE (approximately. miles). The CBCP was initiated with the purpose of: () improving economic conditions, () providing transportation options and improving safety for walkers, cyclists, and motorists, and () enhancing the aesthetic appeal of Capitol Boulevard and encouraging economic development and redevelopment. The CBCP identified congestion along Capitol Boulevard between W Lee Street and Trosper Road SW (about 0 feet) as one of the biggest problems in the area surrounding the Capitol Boulevard /Trosper Road intersection. However, the CBCP did not present any solutions to address this substantial existing congestion problem. The existing problem is characterized by large regional traffic movements for: Southbound I- to eastbound Trosper Road, and then to southbound Capitol Boulevard, and percent of vehicles using the shared through/left turn lane. Southbound vehicles crowd the outside left turn lane because there is only one right turn lane from eastbound Trosper Road to southbound Capitol Boulevard, and northbound vehicles crowd the outside lane because there is only one lane for the northbound I- on ramp from westbound Trosper Road. In cooperation with the Washington State Department of Transportation (WSDOT), the City of Tumwater has identified a Build Alternative that includes modifying four existing intersections along Capitol Boulevard and Trosper Road to incorporate roundabouts, adding new local street connections, and modifying the existing I- northbound interchange. The focus of this I- / Trosper Road Interchange Justification Report (IJR) is on the reconfiguration of the northbound I- interchange with Trosper Road and nearby intersections along Capitol Boulevard. This IJR will evaluate the impacts and benefits of the interchange reconfiguration and intersection modifications. What is the Purpose of the Project? 0 Northbound Capitol Boulevard to westbound Trosper Road and then to northbound I-. There are currently double left turn lanes for the southbound I- off ramp and for Capitol Boulevard northbound at Trosper Road to help accommodate these heavy moves. However, lane balance at both sets of double left turn lanes locations is poor with approximately 0 There is growing concern within the community about congestion and the difficulty of accessing businesses along Capitol Boulevard between Trosper Road and Lee Street. Additionally, the intersection environment for bicycling and walking does not encourage these travel modes. Increasing growth and future redevelopment in the Capitol Boulevard corridor raises questions about the best ways to accommodate growth, while maintaining safe I-/Trosper Road Interchange Justification Report Policy Point Page -

18 Policy Point Need for the Access Point Revision 0 and acceptable levels of mobility for all travel modes. The current WSDOT Highway System Plan, 00-0 Highway System Plan (HSP), does not include any planned projects at the Trosper Road interchange. The purpose of the Interstate /Trosper Road Interchange project is to improve congestion at the intersection of Capitol Boulevard and Trosper Road for vehicular and bicycle/pedestrian traffic. 0 Local Intersections: Littlerock Road/nd Avenue/Trosper Road Capitol Boulevard/Trosper Road Capitol Boulevard/Lee Street The study area and adjacent interchanges on I- are illustrated in Figure -. The adjacent interchanges along I- are Tumwater Boulevard to the south (. miles), Deschutes Parkway to the north (northbound off ramp only, 0. miles) and US 0 to the north (. miles). 0 What is the Purpose of this IJR? The purpose of this I- / Trosper Road Interchange Justification Report (IJR) is to assess the impacts and benefits of the interchange modifications on the northbound I- ramp, at adjacent and nearby intersections. This IJR will evaluate how the proposed Build Alternative will affect overall interstate traffic operations and provide the necessary documentation to justify the interchange modifications. Policy Point documents the need for the interchange modifications, defines existing and future deficiencies, and explains why local transportation improvements and traffic mitigation would not resolve the deficiencies. 0 0 Traffic analysis conducted for the Build Alternative indicates that no substantive change in traffic volumes are expected in the interchange area, but there will be a localized redistribution of traffic through several intersections including Capitol Boulevard/Trosper Road. Build Alternative design would not change at the existing highway ramp gore points on the I- mainline. Accordingly, this IJR does not include analysis of the I- mainline or adjacent interchanges but focuses on the I-/Trosper Road interchange, the intersection of Capitol Boulevard with Trosper Road, and other nearby local intersections. Existing study area intersections are shown in Figure -. 0 What is the Study Area for this IJR? The existing transportation network in the Capitol Boulevard/Trosper Road Intersection study area includes the interchange and the following nearby street intersections: Interchange Intersections: Northbound ramp terminal at Trosper Road Southbound ramp terminal at Trosper Road 0 What are the Analysis Years? This IJR will focus on interchange improvements designed to meet future travel needs. Operational analyses were conducted for the AM and PM peak hours for the following years: Existing Base Year 0 Opening Year 0 Horizon/Design Year 00 I-/Trosper Road Interchange Justification Report Policy Point Page -

19 Policy Point Need for the Access Point Revision Figure -: IJR Study Area and Adjacent Interchanges I-/Trosper Road Interchange Justification Report Policy Point Page -

20 Figure -: Study Area Intersections Policy Point Need for the Access Point Revision I-/Trosper Road Interchange Justification Report Policy Point Page -

21 Policy Point Need for the Access Point Revision 0 What does the Existing Transportation System Include? I- is part of the National Highway System (NHS) and is classified as a Highway of Statewide Significance (HSS). It is a divided highway with three -foot through lanes in each direction through the study area. Access to the local street system in the study area is provided by the I- interchange at Trosper Road. The physical features of this interchange and local streets in the study area are described in the following paragraphs. 0 merges with the loop ramp prior to entering the I- mainline. The southbound loop ramp is used by both directions of traffic on Trosper Road. This interchange provides the primary access to several commercial properties and residential areas on both sides of I-. Figure - shows an aerial view of the existing interchange. Local Streets The following paragraphs describe the prominent streets within the study area. The location of these streets is illustrated in Figure -. I-/Trosper Road Interchange Trosper Road The primary interchange serving the study area is the I-/Trosper Road interchange. This interchange is configured as a partial cloverleaf, with loop ramps serving the northbound and southbound on-ramps. The northbound loop on-ramp serves traffic heading eastbound on Figure -: I-/Trosper Road Interchange 0 Trosper Road has been classified as an arterial by the City of Tumwater. This roadway travels east/west from Capitol Boulevard on the east to th Avenue to the west. Trosper Road is a five lane roadway within the study area and provides access to I-. West of the study area Trosper Road narrows to three lanes, providing access to residential areas. Within the study area Trosper Road has a posted travel speed of mph and provides sidewalks in both directions. No bicycle lanes are provided. Capitol Boulevard 0 Trosper Road Trosper Road, A second northbound on-ramp serves westbound Trosper Road traffic, and Capitol Boulevard is part of the old US north/south highway that served the west 0 coast until the construction of I-. It travels north/south east of I-, and is classified as an arterial by the City of Tumwater. Capitol Boulevard travels from downtown Olympia, through Tumwater and south into Tenino. In the study area Capitol Boulevard provides access to many commercial properties, the WSDOT Olympic Region headquarters and several state office buildings. It provides five travel lanes and sidewalks in I-/Trosper Road Interchange Justification Report Policy Point Page -

22 Policy Point Need for the Access Point Revision both directions through the study area. No bicycle lanes are provided. It has a posted speed limit of mph. Littlerock Road Littlerock Road is a five lane road that has been classified as an arterial by the City of Tumwater. It travels north/south west of I-, from Trosper Road on the north to SR on the south. North of Trosper Road, the street becomes nd Avenue and extends north to the I-/US 0 interchange. Within the study area, Littlerock Road has five travel lanes and provides sidewalks and bicycle lanes in both directions. It has a posted speed of 0 mph. Littlerock Road provides access from the Trosper Road interchange to several commercial properties, including Fred Meyer, Costco, Home Depot and Wal-Mart. Lee Street The City of Tumwater has classified Lee Street as a collector roadway. It travels east/west from Boston Street to Linderson Way, and has two travel lanes. East of Capitol Boulevard, Lee Street serves residential communities. Between Capitol Boulevard and I- Lee Street/Linderson Way provide an alternate route to Capitol Boulevard and serve a mix of residential properties and businesses. Lee Street provides sidewalks in both directions and partial bicycle lanes. Project Study Area Intersections Five existing intersections have been identified for evaluation within the study area. All five of these intersections are currently controlled by traffic signals. Four of these intersections are along Trosper Road and lie within,00 feet of each other between Littlerock Road/nd Avenue/Trosper Road on the west side of I- to Capitol Boulevard/Trosper Road at the east side. The Capitol Boulevard/Lee Street intersection is located about 0 feet south of the Capitol Boulevard/Trosper Road intersection. These intersection locations are illustrated on Figure -. Why is there a Need for Action? As part of the Capitol Boulevard Corridor Plan (CBCP), analysis was conducted of the existing and expected future multimodal transportation system. 00 baseline traffic projections are expected to increase substantively and will result in failing conditions at the Capitol Boulevard/Trosper Road intersection. This will result in excessive queuing and delay on both Capitol Boulevard and Trosper Road, immediately to the east of the I-/Trosper Road interchange. The Capitol Boulevard/Trosper Road intersection is expected to operate at a LOS F with multiple failing movements. This will result in frequent signal cycle failures with queues building throughout the peak period. In the evening peak period the queues will extend over,000 feet to the north and south. In addition to a high level of congestion, the corridor is notable for its lack of continuous bicycle facilities and a poor quality pedestrian environment. Local transit plans have identified the corridor for -minute peak service which requires a strong and supportive walking and bicycling environment. As noted in the introduction to this policy point, the CBCP focuses on enhancing multimodal traffic movement within the study area in support of the corridor s economic and land use vision. A key element of achieving that vision is addressing existing and projected congestion at the I- interchange with Trosper Road and the I-/Trosper Road Interchange Justification Report Policy Point Page -

23 Policy Point Need for the Access Point Revision 0 adjacent intersection of Trosper Road with Capitol Boulevard. Transportation goals of the CBCP include: The interchange of I- at Trosper Road coupled with the adjacent intersections Improve mobility for pedestrian, bicycle, bus, and automobile transportation. Improve pedestrian and bicycle environments. 0 standard of LOS D for transportation facilities within the City and its Urban Growth Area. The only exception to this is the intersection of Capitol Boulevard/Trosper Road where LOS E is the standard. Transportation facilities that function below the adopted standards are determined to be failing. The current versions of Synchro, Sidra and Highway Capacity Manual (HCM) software were used to determine the LOS for all of the intersections and freeway merge/diverge points within the study area. 0 Enhance transit experience and efficiency. Increase automobile safety and movement. Improved I- access will be needed to support planned community growth, and achieve local and regional economic development and quality of life objectives, while providing safe and acceptable levels of service on both local and state transportation facilities. The following sections provide a brief summary of existing (0) and expected future (0 and 00) transportation problems in the study area focusing on the need for access point revisions to the I-/Trosper Road interchange. A more detailed discussion is provided under Policy Point. 0 0 In areas with congestion, vehicle queuing can become a significant operational concern. In addition to LOS, queuing was considered between the closely spaced intersections on Capitol Boulevard and Trosper Road. Sim- Traffic was used to calculate the th percentile queues for all of the study intersections including both through and turning movement lanes. The analyses and procedures used in evaluating traffic operations in the study area are discussed in greater detail in the Transportation Study, Capitol Boulevard/Trosper Road Intersection, Methods & Assumptions Report, contained in Appendix A. What are Current and Expected Future No Build Traffic Conditions? How were Traffic Operations Analyzed? 0 Existing Peak Hour Traffic Conditions Traffic Volumes 0 To identify the operational conditions of the roads and intersections within the study area, two primary performance measures were selected. These are vehicle delay and th percentile queues. Vehicle delay is measured by level of service (LOS). The City of Tumwater has adopted a 0 Traffic volume counts were collected from multiple sources for this analysis. Intersection turning movement counts were obtained for AM and PM peak hours at all key study area intersections. I- mainline volumes were obtained from WSDOT, while intersection AM and PM peak hour traffic volumes were counted I-/Trosper Road Interchange Justification Report Policy Point Page -

24 Policy Point Need for the Access Point Revision specifically for this IJR at each of the study intersections. I- mainline volumes were primarily determined using (Permanent Traffic Recorder) PTR R0, located on I- at milepost 0., south of the I-/US 0 interchange. Volumes at this location were used as control totals for the mainline, with ramp volumes obtained from intersection counts used to generate the other mainline locations. Existing 0 traffic volume data is included in Appendix B. Operations Summary In the morning and evening peak hours, the intersections in the study area generally function well. The primary capacity issues are associated with commute traffic going between Interstate and Capitol Boulevard. Although the intersection LOS is acceptable at each of the study intersections, individual movements experience capacity constraint that can lead to excessive queuing between intersections. Intersection operations and traffic queuing analysis results are presented in tables under Policy Point #. 0 No Build Peak Hour Traffic Conditions Forecasted traffic volumes were developed for the expected year of project opening in 0. This was accomplished using the regional travel demand model developed and maintained by TRPC. The model was adjusted to reflect expected land use and/or transportation system changes in the Brewery District and within the Capitol Boulevard Plan study area, as well as future redevelopment of the WSDOT Olympic Region offices. See discussion under Policy Point # for further details Traffic Volumes AM and PM peak hour turning movement projections for the 0 No Build Alternative are presented in Appendix D. Projected volumes along I- and on the Trosper Road interchange ramps are illustrated in Figure -. Operations Summary Traffic operations analysis was conducted for I- merge/diverge activity at the Trosper Road interchange. As discussed in greater detail under Policy Point #, all merge/diverge points would operate within acceptable performance standards (LOS D or better). Study area intersection operations are expected to degrade from existing operations to LOS C or D during both the AM and PM peak hours. However, substantial traffic queues are expected, particularly at the intersections of Trosper Road with the I- northbound ramp termini and Capitol Boulevard. 00 No Build Peak Hour Traffic Conditions Forecasted traffic volumes were developed for the long range planning horizon or design year of 00 using the TRPC model as described under 0 Peak Hour Conditions. See discussion under Policy Point # for further details. Traffic Volumes AM and PM peak hour turning movement projections for the 00 No Build Alternative are presented in Appendix D. Projected volumes along I- and on the Trosper Road interchange ramps are illustrated in Figure -. Operations Summary Traffic operations analysis was conducted for I- merge/diverge activity at the Trosper Road I-/Trosper Road Interchange Justification Report Policy Point Page -

25 Policy Point Need for the Access Point Revision interchange. As discussed in greater detail under Policy Point #, all merge/diverge points would operate within acceptable performance standards (LOS D or better) with the exception of the southbound diverge point which is expected to operate at LOS E. Study area intersection operations are expected to degrade from existing and projected 0 operations during both the AM and PM peak hours. The intersection of Capitol Boulevard at Trosper Road is expected to operate at LOS F during the AM and PM peak hours. However, substantial traffic queues are expected, particularly at the intersections of Trosper Road with the I- northbound ramp termini and Capitol Boulevard. The intersection of Trosper Road with the I- southbound ramps is expected to operate at LOS E during the AM peak hour and LOS F during the PM peak hour. The intersection of Trosper Road with Littlerock Road/ nd Avenue is expected to operate at LOS E during the PM peak hour. Significant traffic queuing is expected at most study area intersection during both the AM and PM peak hour. Could Local Street Improvements Address I- Interchange Congestion? To address expected congestion in the vicinity of the I-/Trosper Road interchange, the City of Tumwater has proposed to make a series of intersection improvements along Capitol Boulevard. These improvements will add local connectivity and provide alternative routes to and through the commercial and residential area between the freeway and Capitol Boulevard (see illustrations of the proposed improvements in the discussion of Policy Point #). As indicated by the foregoing traffic operations and queuing analysis, a key problem location in the study area is the intersection of Capitol Boulevard and Trosper Road. Congestion at this location impacts the entire I- interchange. Analysis conducted of a range of improvements to this location indicates that there are no reasonable solutions that could be implemented to address this congestion without impacting the configuration of the I- northbound ramps. Not only is the intersection area fully developed with insufficient right-ofway to make major intersection improvements, City and regional policy preclude widening Capitol Boulevard beyond its current five-lane cross-section. These policies speak to broad community support in promoting redevelopment along the corridor, increasing multimodal access, and substantially enhancing existing quality of life in the area. Thus, while proposed local street improvements will significantly help Tumwater traffic circulation, they cannot resolve existing or projected future congestion through the interchange area. Improvements to I- access that allow for a redistribution of local and regional traffic away from the Capitol Boulevard/Trosper Road intersection are essential to meeting the travel needs of this growing community. I-/Trosper Road Interchange Justification Report Policy Point Page -

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27 Policy Point Reasonable Alternatives. POLICY POINT REASONABLE ALTERNATIVES 0 Introduction The purpose of Policy Point # is to describe the process used to develop and evaluate improvement alternatives to address the needs identified under Policy Point #. The evaluation process should address all reasonable alternatives including those affecting only the local street system, only the interstate highway and interchange(s), or both. The assessment should determine which alternatives are viable based the project s purpose, and should identify a preferred course of action. Figure - Study Process to Develop and Evaluate Reasonable Alternatives Figure - illustrates the process used to develop and screen a wide range of alternatives leading to the Build Alternative that is the focus of this IJR. The following pages present highlights of this process. Further information is included in the appendices of this document. 0 How Were Initial Improvement Alternatives Identified? 0 Brainstorming of Ideas A design workshop was held on May, 0 to brainstorm potential improvements to Capitol Boulevard with particular emphasis on its intersection with Trosper Road. The design workshop included representatives from the City of Tumwater, the City of Olympia, the City of Lacey, Thurston County, Thurston Regional Planning Council (TRPC), Intercity Transit and WSDOT. Forty-two ideas were suggested at this workshop to specifically address traffic congestion at the intersection of Capitol Boulevard and Trosper Road. The forty-two 0 ideas including several under each of the following categories: Install roundabouts along Trosper Road Relocate I- northbound on-ramp Improve existing I- northbound onramp Relocate I- northbound ramps (both on and off) Make improvements to intersection of Capitol Boulevard and Trosper Road Other circulation improvements in the area (largely adding localized connectivity) I-/Trosper Road Interchange Justification Report Policy Point Page -

28 Policy Point Reasonable Alternatives Non-construction improvements (ramp metering, signal timing and speed zone changes) Evaluation of Brainstormed Ideas Subsequent to the design workshop, a preliminary analysis was conducted to evaluate the viability of the brainstormed ideas. A simple scoring and ranking analysis was used to screen the ideas down to -0 alternatives. The results of the workshop and subsequent screening were carried forward and used as a starting point by the Support Team for an in-depth transportation study of localized transportation circulation options. See Appendix G for more information about the screening of brainstormed ideas. How Was the Shortlist of Alternatives Developed? The Support Team modified the screened list of alternatives to develop a shortlist of alternative improvements for detailed analysis. The alternatives were grouped into four categories: Base Condition/No Build this would retain the existing traffic signal at the Capitol Boulevard/Trosper Road intersection. 00 Intersection Capacity Alternatives these alternatives would be designed to accommodate 00 traffic regardless of the size of the footprint. Context Sensitive Intersection Capacity Alternatives these alternatives would accommodate 00 traffic volumes, but would be limited in footprint size to fit the scale and context of the existing intersection location Traffic Diversion Alternatives these alternatives would encourage traffic to divert from the Capitol Boulevard/ Trosper Road intersection and use other routes. These alternatives would have the goal of reducing the amount of traffic using the intersection. The following are descriptions of the alternatives: Base Condition /No Build The existing channelization would be retained at the Capitol Boulevard/ Trosper Road traffic signal (total of entering lanes). 00 Intersection Capacity Alternatives Traffic Signal Would include additional through and/or turn lanes to meet forecast Design Year (00) travel demand (approximately total entering lanes). Roundabout Would be designed with circulating and/or bypass lanes to meet Design Year travel demand (i.e., lanes northbound left turn lane, left-thru lane, and thru-right lane; bypass lanes southbound and I-/Trosper Road Interchange Justification Report Policy Point Page -

29 Policy Point Reasonable Alternatives eastbound). A total of entering lanes would be provided. Context Sensitive Intersection Capacity Alternatives 0 Would involve relocation of the northbound offramp and northbound loop on-ramp to Ruby Street. Includes construction of th Avenue between Trosper Road and Lee Street. Double Right Turns 0 Would consist of existing channelization plus one added right turn lane for eastbound Trosper Road traffic (creates dual right turn lanes for a total of entering lanes). Traffic Signal 0 Would include the eastbound double right turn lane describe above and additional northbound through lane. Alternative would be limited to a total of entering lanes. New I- Crossing Would include construction of a new road overcrossing of I- south of and parallel to Trosper Road. Roundabout 0 Would be limited to two circulating lanes with bypass lanes to serve traffic traveling from southbound to westbound and from eastbound to southbound for a total of ten entering lanes. Traffic Diversion Alternatives Ruby Street Ramps 0 Other Alternatives East Leg Closure would involve closing the east leg of the Capitol Boulevard/Trosper Road intersection. North/South Couplet would involve construction of a north-south couplet for Capitol Boulevard traffic between Lee Street and M Street. I-/Trosper Road Interchange Justification Report Policy Point Page -

30 Policy Point Reasonable Alternatives 0 Transit Center Would provide a transit center/park and ride lot close to Tumwater s City Hall and Tumwater Boulevard SW and expand transit and express service between Tumwater and downtown Olympia. How was the Shortlist of Alternatives Evaluated? Subsequent to development of the shortlist of eleven alternatives, the Support Team identified a strategy for evaluating and ranking alternatives by determining which criteria should be used and how they should be weighted and applied. The goals of the Capitol Boulevard Plan informed the development and selection of evaluation criteria. 0 0 Alternatives Analysis The scoring and ranking of alternatives was conducted in a two-step process. Step One involved an initial screening to highlight the most promising options. These options were evaluated in greater detail in Step Two. What were the Results of Step One Screening? The analysis of alternatives was prepared in accordance with the Proposed Alternative Analysis Methodology REVISION memorandum, dated May 0, 0 (see Appendix I). This methodology included: st - Assign relative weights to the eight criteria identified above. 0 0 Evaluation Criteria Final evaluation criteria are based on community goals and included: Advance Corridor and Regional Planning Goals o Meet economic goals o Enhance network connectivity o Improve neighborhoods and the environment Improve Local Network Performance o Operations at Capitol/Trosper (delay and queuing) o Corridor Traffic (delay and queuing) o Service to bicyclists and pedestrians Promote Efficient Operation of I- o I- operations at Trosper Road interchange Safety Impacts o Projected collisions 0 0 nd - Score the performance of the alternatives for each of the eight criteria. A rating of 0 to 0 will be applied to each of the criteria. The rating is then multiplied by the criteria weight to determine the criteria score. The performance score for each alternative is determined by the sum of the weighted criteria scores. rd - Develop project cost estimates for the alternatives. th - Calculate the value of each alternative (performance divided by cost) and identify the highest value alternatives. Scoring of Alternatives by Criteria Table - summarizes the scoring of each alternative relative to the eight criteria that measure performance under the four study objectives. A detailed summary of the evaluation and ranking of shortlisted I-/Trosper Road Interchange Justification Report Policy Point Page -

31 Policy Point Reasonable Alternatives alternatives is included in Appendix I. It should be noted that traffic operations analysis focused only on the PM peak hour, and safety was only scored qualitatively. Table - also presents the total weighted performance scores for each shortlisted alternative. These scores will be used in value ranking the alternatives. Alternative Table -: Summary of Performance Scores for Shortlisted Alternatives Economic Goals Community Goals Connected Network N hoods/ Environ. Operations Capitol/ Trosper Corridor Bike /Ped I- Safety Total Weighted Score Base Condition Capacity-Signal Capacity-Roundabout 0 0. Context- Right Turns 0.0 Context-Signal 0. Context-Roundabout 0. Diversion-Ruby Ramps 0. Diversion-I- Crossing 0 0. Diversion-East Leg Closure Diversion-N/S Couplet 0. Diversion-Transit Center 0. Note: 0 is the lowest possible score and 0 is the highest possible score. See Appendix I for more detailed information about the ranking of alternatives. 0 0 Project Costs Conceptual-level project costs were developed for seven of the most highly scoring alternatives to provide a value ranking for each. Project costs were broken up into right of way and design/construction costs. There is no cost associated with the Base Condition/No Build Alternative. Costs for the transit center were also not included in the Step One analysis. Conceptual costs for the Step One alternatives analysis include capital costs only. It was recommended that the transit alternative be carried forward to the Step Two evaluation at which time, a major component of costs associated with the transit center operations and maintenance could be calculated. Lastly, project costs were not estimated for the following alternatives: Intersection Capacity Traffic signal modifications Traffic Diversion Closure of the east leg of the Capitol Boulevard/Trosper Road intersection These alternatives do not meet the corridor and regional planning goals set forth in the CBCP. Both alternatives would add to the access management problems at the intersection and along Capitol Boulevard immediately south of the intersection. The traffic signal would require a total of lanes entering the intersection with eight lanes on the south leg alone. An intersection of that size is not consistent with the CBCP goals in scale and network connectivity for bicycles and pedestrians. While the intersection would solve I-/Trosper Road Interchange Justification Report Policy Point Page -

32 Policy Point Reasonable Alternatives 0 0 traffic congestion at the intersection, it would be counterproductive to the overall community vision for the area. Subsequently, it was determined that further screening of this alternative was not warranted. Considering the low cost associated with closing the east leg, its value is likely high. However, this alternative would not advance access management and economic goals in the CBCP which encourage added local access coupled with access management along Capitol Boulevard. Closure of the east leg at the Trosper Road intersection would preclude development of a proposed new north/south street east of and parallel to Capitol Boulevard with northerly access on the east leg of the Capitol Boulevard/Trosper Road intersection and southerly access to Lee Street. These improvements would be made in conjunction with access management restrictions along 0 0 Capitol Boulevard. As such, it was determined that further screening of this alternative would not be warranted. Project cost estimates for the seven alternatives considered included right of way acquisition, design and construction. Design and construction cost estimates were developed using the City s standard plans and a review of the 0 WSDOT Unit Bid Item Analysis for the Olympic region. A detailed breakdown of the right of way acquisition, design and construction costs is included in Appendix D of the Capitol Boulevard/Trosper Road Transportation Study, Step One Ranking of Alternatives report dated December 0. Table - presents a summary of the project costs for the seven alternatives. A cost index is also shown which will be used in the value ranking of each alternative. Alternative Table -: Conceptual Level Cost Estimate Summary Right of Way Costs Design and Construction Cost Total Project Cost Cost Index 00 Capacity-Roundabout $,00,000 $,000,000 $,00, Context Sensitive Right Turns $,00,000 $,0,000 $,00, Context Sensitive Traffic Signal $,0,000 $,00,000 $,00, Context Sensitive Roundabout $,0,000 $,0,000 $,0, Diversion Ruby Ramps $,0,000 $,0,000 $,0, Diversion I- Crossing $,0,000 $,0,000 $,00, Diversion North/South Couplet $,0,000 $,0,000 $,0, Note: See Transportation Study, Capitol Boulevard/Trosper Road Intersection, Step One Ranking of Alternatives, Appendix D, SCJ Alliance, September 0, for more detailed information about cost estimating. Value Ranking Dividing the weighted performance scores of the seven remaining alternatives by a cost index derived from the project costs shown in Table - provides a value index for each of the 0 alternatives. The value index is analogous to a benefit/cost ratio. The alternatives with higher value indices provide a greater benefit per unit of cost. Table - includes a summary of the calculated value indices. I-/Trosper Road Interchange Justification Report Policy Point Page -

33 Policy Point Reasonable Alternatives Table -: Value Index for Narrowed List of Alternatives Alternative Performance Scores Cost Index Value Index 00 Capacity-Roundabout Context Sensitive Right Turns Context Sensitive Traffic Signal Context Sensitive Roundabout Diversion Ruby Ramps Diversion I- Crossing Diversion North/South Couplet Note that division of the numbers in this table does not precisely equal the value index for each alternative due to rounding. 0 0 The purpose of the Step One analysis and ranking was to screen the alternatives down to two to four promising candidates, and identify possible combinations of alternatives that could effectively meet the project s purpose and need. Building the Ruby Street Ramps is expected to be the highest value alternative. With a combination of the Ruby Street Ramps and the existing traffic signal, the Capitol Boulevard/Trosper Road intersection would reach a failing level of service (as measured by delay or queue length) by 0. Therefore, it was recommended that some of the alternatives be combined to develop improvement packages that would provide functional operations at the Capitol/Trosper intersection through the design year of 00. Based on the results of the Step One analysis four alternatives or combinations of alternatives were identified for further analysis. These are: Alternative : Ruby Street Roundabout Relocation of northbound Trosper Road ramps to Ruby Street and construction of a roundabout while retaining existing signal at Capitol Boulevard/Trosper Road intersection Alternative : Northbound Ramp and Capitol Roundabouts Combine Alternative (NB ramp roundabout) with a two-lane roundabout at Capitol Road/Trosper Road. The roundabout would include right-turn bypass lanes for southbound Capitol Road to westbound Trosper Road and eastbound Trosper Road to southbound Capitol Road. Alternative : Northbound Ramp Roundabout and Double Right-Turn Lanes Combine Alternative (NB Ramp Roundabout at Ruby Street) with double right turn lanes from eastbound Trosper Road to southbound Capitol Boulevard. Alternative : Capitol Roundabout with Transit Combine Capitol/Trosper roundabout with increased transit ridership in the Capitol Boulevard corridor to reduce the traffic volume in the Capitol/Trosper intersection. As previously mentioned, project costs were not developed for the transit center alternative. The operational results warrant a closer look into this alternative. Therefore, it has also been included in the final four alternatives for in- I-/Trosper Road Interchange Justification Report Policy Point Page -

34 Policy Point Reasonable Alternatives 0 0 depth evaluation. Capital facility and operations/maintenance costs were developed as part of the Step Two evaluation to establish a value index for comparison to other alternative combinations. What were the Results of Step Two Screening? The scoring and ranking of alternatives was prepared in accordance with the Proposed Alternative Analysis Methodology REVISION memorandum, dated May 0, 0 (see Appendix H). This methodology calls for the following steps: Assign relative weights to the eight criteria previously discussed. Score the performance of the four alternatives for each of the eight criteria. Develop project cost estimates for the four alternatives. Calculate the value of each alternative (performance divided by cost) and identify the highest value alternative. 0 0 Criteria and Weighting There are four main objectives for the project: () Advancing corridor and regional planning goals identified in the CBCP, () Improving local network performance, () Promoting efficient operation of I- mainline and the Trosper Road ramps, and () Promoting safety for vehicles, bikes and pedestrians. The eight criteria were grouped under these four objectives. The Support Team developed weights (relative importance) for the criteria by using pair-wise comparisons. The highest weighted criteria were Operations at Capitol/Trosper and Capitol Corridor Operations. Scoring of Alternatives by Criteria Table - summarizes scoring of the four final alternatives relative to the eight criteria that measure performance under the four study objectives. Table - also presents the total weighted performance scores for each alternative. These scores will be used in value ranking the alternatives. A more in-depth discussion of the evaluation process is provided in the text below. Alternative Table -: Evaluation Summary of Four Final Alternatives Economic Goals Community Goals Network Performance Total Connected Network N hoods/ Environ. Capitol/ Trosper Corridor Bike/ Ped I- Safety Weighted Score Ruby Roundabout 0. Ruby and Capitol/ Trosper Roundabouts Ruby Roundabout & Double Eastbound Rights Capitol/Trosper Roundabout with Transit Note: 0 is the lowest possible score and 0 is the highest possible score. I-/Trosper Road Interchange Justification Report Policy Point Page -

35 Policy Point Reasonable Alternatives Advance Corridor and Regional Goals The criteria are measured qualitatively based on how they advance the CBCP goals and whether or not they provide the opportunity to further advance the goals. Included are: Economic Conditions increasing the attractiveness for property owners and developer to redevelop along the corridor. Network Connectivity creating a multimodal street network and local access consistent with the CBCP. Neighborhoods/Environment creating neighborhoods and environmental changes and aesthetics consistent with the CBCP. As illustrated in Table -, Alternative with the roundabouts at Ruby Street and at the Capitol Boulevard/Trosper Road would be the most effective in meeting these criteria. Improve Local Network Performance These criteria focus on traffic operational performance in the study area with an emphasis on the intersection of Capitol Boulevard and Trosper Road. Improvements to bicycle and pedestrian mobility and access were also assessed. Table - shows the scoring for the network performance criteria including: Capitol Boulevard/Trosper Road Operations minimize peak hour queue length (linear feet) and peak hour intersection delay (seconds). Local Intersection Operations minimize peak hour queue length (linear feet) and peak hour intersection delay (seconds) for other study area intersections Bicycle and Pedestrian Access provide mobility and access to transit for bicycles and pedestrians through/near the Capitol/Trosper intersection and along the corridor. This criterion was measured qualitatively. As shown in Table -, Alternative provides superior performance. More detailed information about traffic operations analysis conducted for the final four alternatives can be found in Appendix J. This analysis included stop control at the Trosper Road/ th Avenue intersection. Upon review of the signing plan the project team, with input from the stakeholder team, recommends roundabout control at this intersection. The addition of this roundabout has improved the overall performance of Alternative and the operational analysis results are discussed below in Policy Point. Promote Efficient Operation of I- (Mainline and Ramps) This criterion addresses impacts to the operations of I- at the Trosper Road ramp terminals and the merge/diverge points. The scoring considers the levels of service (LOS) of the merge/diverge points and the delay/queue at the ramp terminals. Table - shows the results of this analysis which indicates that Alternatives and would provide the greatest benefit. Safety The safety analyses used two different predictive safety models: the Highway Safety Manal Part C (HSM Part C) and the Enhanced Interchange Safety Analysis Tool (ISATe). The Highway Safety Manual (HSM) Part C safety analysis was used to determine the predicted safety performance of each Step Two I-/Trosper Road Interchange Justification Report Policy Point Page -

36 Policy Point Reasonable Alternatives alternative at the urban arterial intersection of Capitol Boulevard and Trosper Road. The Enhanced Interchange Safety Analysis Tool (ISATe) was used to determine the predicted safety performance of each of the Step Two alternatives as they related to the interchange facilities (i.e., ramp segments and ramp intersections). Like the HSM Part C method described above, this tool is based on the predictive method included in Part C of the Highway Safety Manual. The ISATe provides information about the relationship between roadway geometric design features and safety. It is based on research that quantifies the relationship between various design elements and average crash frequency. The major inputs for this predictive tool are roadway segment length and width, curve radius, traffic volume, and accident history. These tools were used to determine the predicted average crashes per year at the focus intersections for each alternative. Results were then used to score each alternative for safety. These predictive models did not allow for roundabout control, so for the alternatives with a proposed roundabout the score was adjusted higher to approximate a crash modification factor of 0. for a roundabout in comparison to a traffic signal. In addition to the quantitative data provided by these predictive tools, the pedestrians and bicycles safety of each alternative was also qualitatively assessed. The overall safety scores shown in Table - are comprised of the quantitative predicative tools and the qualitative assessment. As indicated in the Table, Alternatives and are expected to provide superior safety Project Costs Conceptual-level project costs were developed in order to provide a benefit/cost ranking for each alternative. Project costs are broken up into right of way, design/construction costs, and life cycle costs. Right of Way Acquisition Each one of the alternatives will require purchasing right of way. Estimated right of way requirements are based on conceptual-level layouts using City-provided right of way lines along Capitol Boulevard. Thurston County Geodata was used to estimate existing right of way boundaries not included in the Cityprovided data. The parcel values are based on the 0 Thurston County assessed values. Design and Construction Costs Design and construction cost estimates were developed using the City s standard plans and a review of the 0 WSDOT Unit Bid Item Analysis for the Olympic region. Life Cycle Costs A life cycle cost is included to compare the costs of increased transit ridership to the - year life cycle costs for asphalt concrete pavement. Analysis of life cycle costs includes supporting ridership data from Intercity Transit. Table - includes a summary of the project costs for the four alternatives. A cost index is also shown which will be used in the value ranking of the alternatives. Value Rankings Dividing the weighted performance scores of the four alternatives by a cost index derived from the project costs shown in Table - provides a value index for each of the alternatives. The value index is analogous to a I-/Trosper Road Interchange Justification Report Policy Point Page -0

37 Policy Point Reasonable Alternatives benefit/cost ratio. The alternatives with the higher value indices provide a greater benefit per unit of cost. Alternative Table -: Cost Summary for Final Four Alternatives Right of Way Design and Construction Life Cycle Total Project Cost Index Ruby Roundabout $,0,000 $,0,000 $,000 $,, Ruby and Capitol/Trosper Roundabouts Ruby Roundabout and Double Eastbound Rights Capitol/Trosper Roundabout with Transit $,00,000 $,0,000 $,000 $,, $,0,000 $,0,000 $,000 $,, $,0,000 $,0,000 $,,000 $,0, Note: See Transportation Study, Capitol Boulevard/Trosper Road Intersection, Step Two Ranking of Alternatives, Appendix E, SCJ Alliance, September 0, and updated analysis dated October, 0 for more detailed information about cost estimating. $,0,000 of life cycle costs for Alternative are related to transit, $,000 are related to pavement. 0 Table - includes a summary of the calculated value indices. As indicated in the table, Alternative (the northbound Ruby Street ramp roundabout) yields the best value, followed by Alternative (which adds a roundabout at the Capitol Boulevard/Trosper Road intersection) which scored the best among the combination alternatives. Alternative (a combination of Alternative with dual eastbound right turn lanes on Trosper 0 Road at Capitol Boulevard) scored closely below Alternative due to its relatively low cost. However, it ranked third in overall performance relative to the project s objectives to advance the vision of the CBCP. Alternative (including the Capitol/Trosper roundabout with transit improvements) did not provide a relative performance benefit, and increased life cycle costs substantially. Table -: Value Index for Final Alternatives Alternative Performance Scores Cost Index Value Index Ruby Roundabout Ruby and Capitol/Trosper Roundabouts Ruby Roundabout and Double Eastbound Rights Capitol/Trosper Roundabout with Transit Note that division of the numbers in this table does not precisely equal the value index for each alternative due to rounding. I-/Trosper Road Interchange Justification Report Policy Point Page -

38 Policy Point Reasonable Alternatives What Improvements are Recommended for a Build Alternative? A variation on Alternative is recommended as the Build Alternative. It includes the addition of a roundabout on the I- northbound off-ramp at approximately Ruby Street, development of th Avenue between Trosper Road and T Street and the addition of another roundabout at the intersection of th Avenue with Trosper Road. These improvements would be coupled with a multi-lane roundabout at the Capitol Boulevard/Trosper Road intersection. The roundabout on Trosper Road at th Avenue was added to the original Alternative concept in response to further consultation among project stakeholders during the development of this IJR. While Alternative (only including the Ruby ramp roundabout) provides the highest value index, it does not provide the desired operations at the Capitol Boulevard/Trosper Road intersection over the long term to 00. Building all three roundabouts in a phased approach provides desirable operations and would better meet the objectives of the CBCP. These include greater opportunity for improved economic conditions, adding network connectivity, enhancing neighborhoods and the built environment, improving bicycle and pedestrian connectivity, improving safety, and enhancing I- operations. This project, from its inception as part of the CBCP to identification of a Build Alternative, demonstrates that Tumwater is aligning its investments and policies with its vision. The city is taking a pragmatic, practical approach to taming highway-oriented traffic and reclaiming its local streets for all modes of travel in support of a strong and diverse local economy and thriving neighborhoods. Proposed Build Alternative improvements are illustrated in Figure -. Phasing Analysis The phasing of improvements is an important element of WSDOT s Practical Design process which recommends that infrastructure investment be timed to match the projected need. While the alternatives considered in this IJR were each evaluated for peak hour performance in 00, not all of the elements of the best performing alternative (a variation of Alternative ) are needed immediately. The operational performance, potential for independent utility, and project costs all lend themselves to a phased approach combining the two distinct elements of this Alternative modifications to the northbound off-ramp including the roundabouts at Ruby Street and Trosper Road, and the Capitol Boulevard/ Trosper Road multilane roundabout. To better understand the operational benefits of Alternative with its component projects and to provide insight into potential project phasing, an analysis was conducted of the expected year of failure for several scenarios. Table - summarizes the results of this analysis. Table -: Projected Traffic Operations Failure Year Improvement Scenario Failure Year No build Condition 00 Ruby & Trosper Roundabouts 0 Capitol/Trosper Roundabout 00 Ruby and Capitol/Trosper Roundabouts 00 Phasing will likely be constrained by available funding. Each of the roundabouts is projected to cost between $ and $ million (project costs I-/Trosper Road Interchange Justification Report Policy Point Page -

39 Policy Point Reasonable Alternatives Figure -: Recommended Build Alternative Improvements I-/Trosper Road Interchange Justification Report Policy Point Page -

40 Policy Point Reasonable Alternatives including design, right of way, and construction). This project size matches well with typical grant-funded projects (i.e., TIB UAP Grants). Phasing Recommendations It is recommended that the Build Alternative be constructed in two phases: Phase : Construct th Avenue between Trosper Road and T Street, and the northbound I- ramp roundabout at Ruby Street. Phase : Construct the roundabout at Capitol Boulevard/Trosper Road. The construction of the third roundabout, at Trosper Road/ th Avenue, does not provide independent benefit but rather compliments the primary roundabouts and allows the current access at Trosper Road to be maintained. Either primary roundabout can operate without the construction of this third roundabout, which allows this roundabout to be included as part of either phase of the project. It is recommended that the northbound ramp roundabouts be built in Phase because it offers the most initial operational benefit and provides the most time before Phase is needed. Building the northbound ramp roundabouts first also provides a significant advantage in the management of traffic during construction of the Capitol Boulevard/ Trosper Road roundabout, since traffic destined for northbound I- will be able to access the freeway in an alternative location. If the Capitol Boulevard/Trosper Road roundabout is built first, all traffic destined for northbound I- must travel through the intersection while it is under construction. Phase should be completed prior to 00, which is the projected failure year for the No Build Alternative. Phase is projected to extend the life of the Capitol Boulevard/ Trosper Road intersection by years, which provides time to construct Phase. Phase should be completed by 0 to extend the life of the intersection to 00. What improvement Concepts Were Considered and Rejected? Out of the shortlisted alternatives evaluated under Step One, two improvement concepts were initially considered but rejected. As discussed earlier in this report they include: 00 Intersection Capacity Traffic Signal Modifications This scenario would involve full buildout of the Capitol Boulevard/Trosper Road intersection to accommodate all expected future demand. A total of entering lanes would be required which is substantively inconsistent with the goals of the CBCP that limits intersection size and stresses the importance of bicycle and pedestrian connectivity. Traffic Diversion Closure of the east leg of the Capitol Boulevard/Trosper Road Intersection This alternative would not advance access management and economic goals in the CBCP. The parcels east of the intersection would see a significant reduction in business due to access limitations, and would likely constrain redevelopment activity in the area. I-/Trosper Road Interchange Justification Report Policy Point Page -

41 Policy Point Operational and Collision Analyses. POLICY POINT OPERATIONAL AND COLLISION ANALYSES Introduction Policy Point in this IJR summarizes the transportation operations and safety impacts associated with the Build Alternative. This alternative includes re-configuration of the I- northbound interchange at Trosper Road, as well as local street improvements along the Capitol Boulevard corridor. The purpose of these improvements is to address constraints at the interchange and nearby Capitol Boulevard/Trosper Road intersection, thus providing congestion relief and supporting the transportation, land use and economic goals of the CBCP. Proposed improvements in the Build Alternative are illustrated in Figure - and include: Modifications to the I- northbound ramps at Trosper Road The addition of a multilane roundabout at the intersection of Capitol Boulevard and Trosper Road. Additional local improvements along Capitol Boulevard south of Trosper Road Traffic analysis for this IJR evaluated nearterm transportation conditions in the study area for 0, as well as performance in the 00 design year. Overall, analysis shows that the proposed modifications at the I- northbound interchange with Trosper Road, together with several local roadway and intersection projects, will improve the safety and operation of the interchange and ramp intersections. The modified interchange, with associated local street improvements, would improve operating conditions in 0 and continue to provide some operational benefits in 00. How was the Traffic on I- and at Intersections Analyzed? Existing and forecasted traffic data were analyzed to identify how the current transportation system is performing, how traffic levels are expected to grow in the future, and how the proposed improvements in the Build Alternative would impact expected traffic conditions. Traffic analysis focuses on the operational and safety performance of the Build Alternative for AM and PM peak hours in the following years: 0 (existing base year) 0 (anticipated year of opening) 00 (long-term design year) The analyses and procedures used in evaluating traffic operations on I- at Trosper Road and at key corridor intersections are summarized in the Methods & Assumptions Report for the I- /Trosper Road Northbound Ramps Modification contained in Appendix A. The analyses of traffic on I- focused on merge and diverge operations at the interchange. As noted under Policy Point and further discussed under Policy Point, traffic analysis conducted for the Build Alternative indicates that no substantive change in traffic volumes are expected in the interchange area, but there would be a localized redistribution of traffic through several intersections including Capitol Boulevard/Trosper Road. The proposed Build Alternative design would not change the existing highway ramp gore points on the I- I-/Trosper Road Interchange Justification Report Policy Point Page -

42 Policy Point Operational and Collision Analyses mainline. Accordingly, this IJR does not include analysis of the I- mainline or adjacent interchanges, but focuses on the I-/Trosper Road interchange, the intersection of Capitol Boulevard with Trosper Road, and other nearby local intersections. Intersection operations were analyzed using data outputs from the TRPC regional travel demand model. This data was post-processed to identify turning movement projections and assessed using Synchro software for signalized and non-signalized intersections, and Sidra software for roundabouts in accordance with the Highway Capacity Manual (HCM). Safety analysis includes a summary of recent collision experience, and presents a comparison of the No Build and Build Alternatives using the FHWA s ISATe Safety Model. What is the Existing and Proposed Spacing of Interchanges along the I- Corridor within the Study Area? The existing and proposed spacing of interchanges and interchange configurations for the No Build Alternative and the proposed Build Alternative are the same. The Build Alternative would not alter existing interchange ramp access locations or configurations where they enter or leave the freeway mainline. Current design standards suggest that the minimum spacing between urban interchanges should be at least one mile. The existing spacing between the Trosper Road interchange and Tumwater Boulevard interchange to the south is approximately. miles. The existing spacing between the Trosper Road interchange and the US 0/Deschutes Way ramp to the north is approximately. miles. Thus, the design standard for minimum spacing would be met in both directions. How is Existing (0) Traffic Operating in the Study Area? Analysis of existing traffic operations in the vicinity of the I-/Trosper Road interchange focused on: Ramp analysis including merge and diverge points on the I- mainline at the Trosper Road interchange Northbound and southbound ramp terminal intersection operations Operations at other nearby intersections Transportation Performance Measures As noted in Policy Point #, to identify the operational conditions of the roads and intersections within the study area, two primary performance measures were selected vehicle delay and th percentile vehicle queues. Vehicle delay is measured by level of service (LOS). The City of Tumwater has adopted a standard of LOS D for transportation facilities within the City and its Urban Growth Area. The only exception to this is the intersection of Capitol Boulevard/Trosper Road where LOS E is the standard. Transportation facilities that function below the adopted standards are determined to be failing. The current versions of Synchro (Version ), Sidra (Version.0) and Highway Capacity Software or HCS (Version.) were used to determine the LOS for all of the intersections and freeway merge/diverge points within the study area. I-/Trosper Road Interchange Justification Report Policy Point Page -

43 Policy Point Operational and Collision Analyses Figure -: I-/Trosper Road and Capitol Boulevard Improvements in the Build Alternative I-/Trosper Road Interchange Justification Report Policy Point Page -

44 Policy Point Operational and Collision Analyses This Page Intentionally Left Blank I-/Trosper Road Interchange Justification Report Policy Point Page -

45 Policy Point Operational and Collision Analyses 0 In areas with congestion, vehicle queuing can become a significant operational concern. In addition to LOS, queuing was considered between the closely spaced intersections on Capitol Boulevard and Trosper Road. Sim- Traffic was used to calculate the th percentile queues for all study intersections including both through movements and vehicle turning lanes. 0 Interchange Ramp Analysis A merge/diverge analysis was conducted to evaluate existing conditions at the interchange of I- with the northbound and southbound ramps to Trosper Road. The results of this analysis are intended to serve as a baseline 0 condition for use in comparing the No Build and Build Alternatives in 0 and 00. Results of the analysis are presented in Table -. As indicated in the table, all merge/diverge points for both the northbound and southbound ramps currently operate at Level of Service (LOS) D or better. Unlike intersections, for freeway operations the level of service is based on vehicular density (expressed as passenger car equivalents per lane per mile and shown in parenthesis in Table -). Merge/diverge analysis worksheets are found in Appendix C. Table -: 0 Existing Merge/Diverge Analysis Results Levels of Service (LOS) Merge/Diverge Point AM Peak Hour PM Peak Hour Northbound I- Diverge Point C (.) C (.) Northbound I- Merge Point C (.) C (.) Southbound I- Diverge Point C (.) D (.) Southbound I- Merge Point B (.0) B (.) Intersection Operations Analysis As shown in Table -, in the morning and evening peak hours the intersections in the study area generally function well. The primary capacity issues are associated with commute traffic going between Interstate and Capitol Boulevard. Although the intersection LOS is acceptable at each of the study intersections, individual movements experience capacity constraint that can lead to excessive queuing between intersections. Existing queuing issues at key locations are shown in Table -. The following periodic deficiencies are noted: Traffic occasionally backs up on eastbound Trosper Road from Capitol 0 0 Boulevard through nd Avenue. This primarily occurs in the morning peak. During the evening peak the queue on northbound Capitol Boulevard at Trosper Road extends through the Lee Street intersection. Short merge/weave areas on Trosper Road, both east and westbound, result in unequal usage of dual turn lanes. The southbound left-turn lanes on the southbound I- off-ramp and the northbound left-turn lanes on Capitol Boulevard at Trosper Road experience lane imbalance of up to 0/0 which results in less efficient intersection operation. I-/Trosper Road Interchange Justification Report Policy Point Page -

46 Policy Point Operational and Collision Analyses Table -: 0 Existing Peak Hour Intersection Operations AM Peak Hour PM Peak Hour Intersection Intersection Control Mobility Standard LOS (Delay) Worst V/C Ratio LOS (Delay) Worst V/C Ratio Trosper Littlerock Rd/ nd Ave Signal D C () 0. D (0) 0. I- SB Trosper Road Signal D C () 0. D () 0. I- NB Trosper Road Signal D B () 0. D () 0. Capitol Road Signal E C () 0. D () 0. Capitol Lee Street Signal D C (0) 0. D () The assessment of existing intersection traffic operations also includes a review of vehicle queuing. A vehicle queue is the technical term for the number of stopped vehicles waiting to travel through or turning at an intersection. In this analysis, the th percentile maximum back of queue (measured in feet) has been estimated for each travel lane at key study area intersections. The th percentile queue is defined to be the queue length that has only a -percent probability of being exceeded during the analysis period. It is a useful parameter for determining the appropriate length of turn pockets, but it is not typical of what an average drive would experience. The queuing analysis was performed using the Sim- Traffic software package. Five simulations were run for each analysis period and the average is reported in Table -. Queuing analysis was performed for both the AM and PM peak hours. As shown in Table -, existing queuing problems are focused on the intersections of 0 Trosper Road with the I- north and southbound ramps and Capitol Boulevard where some existing queue spillback is experienced. The most significant queues are experienced during the AM peak hour on the I- southbound ramp at Trosper Road. Some minor spillback is also experienced on Trosper Road at nd Avenue and on Lee Street at Capitol Boulevard. 0 intersection operations and queuing analysis worksheets are included in Appendix C. Intersection Level of Service (LOS) Criteria LOS Signalized Intersection Delay (sec) Unsignalized Intersection Delay (sec) A 0 sec 0 sec B 0 0 sec 0 sec C 0 sec sec D sec sec E 0 sec 0 sec F 0 sec 0 sec Source: 00 Highway Capacity Manual I-/Trosper Road Interchange Justification Report Policy Point Page -

47 Policy Point Operational and Collision Analyses Table -: 0 Existing Peak Hour Traffic Queuing at Key Locations Vehicle Queues Intersection Vehicle Storage AM Peak Hour PM Peak Hour Trosper Littlerock Rd/nd Ave Northbound Left 0 ft ft ft Northbound Right 0 ft ft ft Southbound Left 0 ft ft ft Southbound Thru/Right 0 ft ft ft Eastbound Left 00 ft 0 ft ft Westbound Left 00 ft ft ft I- SB Ramp/Tyee Trosper Road Northbound Left 00 ft ft ft Northbound Right 00 ft ft ft Southbound Left 0 ft,0 ft ft Southbound Thru,00 ft,0 ft 0 ft Southbound Right 0 ft ft ft Eastbound Left 00 ft ft 00 ft Eastbound Right 0 ft ft ft Westbound Left 0 ft ft ft Westbound Thru,0 ft ft ft Westbound Thru/Right,0 ft ft ft I- NB Trosper Road Northbound Left,00 ft ft ft Northbound Right 00 ft ft ft Eastbound Thru 00 ft ft ft Eastbound Thru/Right 00 ft 0 ft ft Westbound Thru/Right 0 ft 0 ft 0 ft Capitol Trosper Road Northbound Left 00 ft ft 0 ft Northbound Thru/Left 0 ft ft 0 ft Northbound Thru/Right 0 ft ft 0 ft Southbound Thru >,000 ft ft ft Southbound Left 00 ft ft 0 ft Southbound Right 00 ft ft ft Eastbound Left ft ft 0 ft Eastbound Right 0 ft ft 0 ft Capitol Lee Street Northbound Thru 0 ft ft 0 ft Southbound Left 00 ft ft ft Southbound Thru/Right 0 ft 0 ft ft Eastbound Thru/Left 00 ft ft ft Eastbound Right,00 ft ft ft Bold results indicate locations where existing traffic queues may exceed available vehicle storage space. Reflects th percentile traffic queues. 0 Lane Utilization One of the significant factors contributing to congestion and queue issues along both northbound Capitol Boulevard and the 0 southbound I- off-ramp is the unbalanced lane utilization. Because northbound access to I- from westbound Trosper Road can be made only from the outside lane, upstream traffic from northbound Capitol Boulevard destined I-/Trosper Road Interchange Justification Report Policy Point Page -

48 Policy Point Operational and Collision Analyses for this ramp tends to congregate in the righthand turn lane at Trosper Road, even though two lanes are provided. Because of the heavy volumes making the movement from northbound Capitol Boulevard to northbound I-, there is a significant imbalance between traffic using the two lanes. The southbound I- off-ramp left-turn onto eastbound Trosper Road dominates traffic movement during the AM peak hour at this intersection. As a significant share of this traffic is destined for southbound Capitol Boulevard, the balance between traffic in the existing two left turn lanes is skewed towards the inside lane which leads into the correct lane for turning right at Capitol Boulevard. How were Peak Hour Traffic Volumes Forecast in the Study Area? Forecasted traffic volumes were developed for the expected year of project opening in 0, and the long range planning horizon or design year of 00. This was accomplished using the regional travel demand model developed and maintained by TRPC. This model combines the area s demographic forecasts and local highway networks to identify potential growth in existing peak hour volumes on roadway segments compared to existing conditions. The forecasts were built on 0 base year traffic counts using the following estimation process: Modifications were made to the existing TRPC regional model. A traffic assignment model was run for the future year of 0 to determine annualized traffic volume growth factors for the study area. Traffic volume growth factors were applied to the existing 0 turning movement counts at study area intersections to develop projected 0 and 00 AM and PM peak hour turning movements. Each of these steps is described in the following paragraphs. Modifications to Existing Regional Travel Demand Model The traffic volume projections used in this analysis were prepared using the TRPC regional Emme/ travel demand model. This model is based on 00 traffic conditions and provides traffic volume estimates for both the AM and PM peak hours. The future forecast year of the model at the time operations analysis for this IJR was conducted was 0. This model is based on regionally adopted household and employment projections for the region that are consistent with comprehensive land use plans. The 0 scenario also includes all roadway improvements identified in Thurston County s current Regional Transportation Plan (RTP). Specific enhancements were made to both the 00 and 0 regional models to provide more detailed distribution and assignment of forecasted trips in the study area. Additional enhancements were incorporated from the recent Brewery District planning effort. Below is a description of the model enhancements made as a part of this IJR. Brewery District Model Enhancements Conducted in 0, the Brewery District planning effort included several enhancements to Tumwater portion of the model. Multiple Traffic Analysis Zones (TAZ s) were added to improve the assignment of traffic volumes on local streets that included the vicinity of the I- /Trosper Road interchange. Additionally, several model links were refined to better I-/Trosper Road Interchange Justification Report Policy Point Page -

49 Policy Point Operational and Collision Analyses 0 reflect current roadway connections and conditions. In addition to enhancing the zonal level of detail, the following roadway improvements were reflected in the 0 model scenarios: Interstate was widened to travel lanes in each direction from Exit to Exit 0 to accommodate predicted regional growth. The E Street extension was added to the network. E Street is a proposed / lane roadway connecting Capitol Boulevard and Cleveland Avenue across the Deschutes River valley. 0 0 Traffic analysis zonal centroid connectors along Capitol Boulevard were relocated to better reflect current conditions. T Street was added to the model network. Future Land Use For the 0 model scenario, the land use for the existing WSDOT site was customized to reflect proposed over mixed use development (i.e., four stories of residential development over ground floor retail and commercial uses) from the CBCP (January 0). 0 Household and employment projections were increased to represent redevelopment of the brewery property. Capitol Boulevard Corridor Model Enhancements In addition to the brewery district model enhancements, several additions were made to the roadway network to improve detailed traffic assignment in the study area: An additional segment of Linderson Way was added to the model network from Israel Road to Lee Street. During the preliminary model runs for Tumwater Brewery District Study, it became evident that the capacity along I- was inadequate to accommodate all of the future demand through southern Thurston County. This was causing a large amount of traffic to divert to Capitol Boulevard though the study area to bypass I-. So, while there is no current plan to widen I- in this area, the assumption was made that I- will carry a fourth travel lane in each direction if the demand ever gets to the levels predicted in the 0 model. This roadway improvement would run from the I-/US 0 junction south to the th Avenue interchange. 0 0 Develop and Apply Annualized Traffic Volume Growth Rates While the model is calibrated to replicate existing travel patterns, modeled traffic volumes on individual roadways vary somewhat from existing traffic counts. To account for this variation, annualized model traffic growth rates were calculated for the study area and applied to the existing 0 count volumes. Growth rates were developed using the weighted average of AM and PM peak hour growth at all of the major entry points to the study area. Annualized growth rates of approximately. percent were identified during both time periods. For the No Build Alternative, this growth rate was then applied to the existing 0 volumes as a straight line growth over eight years to calculate the projected 0 opening year traffic volumes, and over years to calculate the projected 00 traffic volumes. Additional modifications to estimate traffic volumes were made to reflect shifts that are expected to occur as a result of the local improvements identified in the CBCP. The CBCP I-/Trosper Road Interchange Justification Report Policy Point Page -

50 Policy Point Operational and Collision Analyses calls for improvements east of Capitol Boulevard from Lee Street up to Trosper Road to allow for the properties in that area to access Capitol Boulevard at Trosper Road. This is expected to reduce the number of vehicles making right turns onto northbound Capitol Boulevard at Lee Street, Ruby Street and Linda Street. All of these movements were reduced significantly in the AM and PM peak hours and assigned as westbound through trips at the Trosper Road/Capitol Boulevard intersection. To develop future traffic projections for the Build Alternative, the specific network changes associated with this alternative were incorporated and a new modeled traffic assignment was run. The expected change in projected volumes between the No Build model and the Build model was identified for each roadway link. This change in volumes was then added to or subtracted from the 0 and 00 No Build intersection turning movement projections to obtain turning movement projections for the Build Alternative. Some further manual adjustments to the model s assignment were made for specific movements such as turning volumes from northbound Capitol Boulevard to westbound Trosper Road to reflect impacts associated with expected congestion levels. The AM and PM intersection turning movement projections for the 0 and 00 No Build and Build Alternatives are presented in Appendix D. How do the Proposed Access Modifications Improve 0 Opening Year Operations at the I- /Trosper Road Interchange? The discussion in this section compares future traffic projections and operational analysis results for both the No Build and Build Alternatives in the 0 AM and PM peak hours. Given the nature of proposed access modifications with the Build Alternative and their limited effect on total freeway ramp volumes at the Trosper Road interchange, traffic operations analysis focused on: Ramp analysis including merge and diverge points on the I- mainline Ramp terminal intersection operations Operations at other nearby intersections 0 Interchange Ramp Analysis A merge/diverge analysis was conducted for the projected 0 No Build Alternative, as well as the Build Alternatives which includes the relocation of the northbound Trosper Road ramps south to an alignment with Ruby Street. Overall traffic volumes with the Build Alternative are expected to change very little from the No Build Alternative. This is because, while the Build Alternative results in significant reassignment of traffic across the city street system, the improvements do very little to change the volume of traffic using the interchange. The merge/diverge analysis results for the 0 AM and PM peak hours are presented in Table - and illustrated with projected PM peak hour volumes in Figure -. As indicated in the table, the AM peak hour would degrade slightly from existing conditions for the southbound diverge point (i.e., LOS C to LOS D) but all merge/diverge points would remain within acceptable performance standards (LOS D or better). The numeric values illustrated in this table reflect estimated vehicular density (expressed as passenger car equivalents per lane per mile). I-/Trosper Road Interchange Justification Report Policy Point Page -0

51 Policy Point Operational and Collision Analyses Figure -: 0 PM Peak Hour Comparison of Mainline Volumes and Operations I-/Trosper Road Interchange Justification Report Policy Point Page -

52 Policy Point Operational and Collision Analyses Merge/Diverge Point Table -: Projected 0 Merge/Diverge Analysis Results No Build Alternative AM Peak Hour Build Alternative No Build Alternative PM Peak Hour Build Alternative Northbound I- Diverge Point C (.) C (.) C (.) C (.) Northbound I- Merge Point C (.) C (.) C (.) C (.) Southbound I- Diverge Point D (.) D (.) D (.) D (.) Southbound I- Merge Point B (.) B (.) C (0.) C (0.) 0 0 When comparing the 0 No Build and Build Alternatives, the northbound I- diverge point would experience the largest change in density value during the AM peak hour, resulting from an increase in the traffic using the northbound I- off-ramp with the Build Alternative. However, the expected level of service would not change. In the PM peak hour all of the merge/diverge points would experience only decimal level changes in density values. The southbound I- diverge point is projected to operate at an LOS D with both the No Build and Build Alternatives. The Build Alternative is expected to slightly increase the density, as a result of an additional 0 vehicles projected to use the southbound off-ramp. The merge/diverge analysis worksheets are in Appendix E for the No Build Alternative and Appendix K for the Build Alternative. 0 AM Peak Hour Intersection Operating Performance 0 0 Build and Build Alternatives at key intersections in the vicinity of the I-/Trosper Road interchange. These intersections are illustrated in Figure -. As indicated in the table, AM peak hour traffic operations would substantially improve with the Build Alternative in comparison to the No Build Alternative. Particularly significant would be the anticipated improvements at the intersection of Trosper Road at Capitol Boulevard with the addition of the proposed multi-lane roundabout where performance is expected to improve from LOS C to LOS A. The conversion of the existing northbound ramp termini intersection at Trosper Road to a roundabout with the construction of th Avenue is expected to provide significant improvement, from LOS D to LOS A. The new intersections of th Avenue with the I- northbound ramp termini and Lee Street would also operate extremely well (LOS A and LOS B, respectively). Table - presents a comparison of 0 traffic operations during the AM peak hour for the No I-/Trosper Road Interchange Justification Report Policy Point Page -

53 Policy Point Operational and Collision Analyses Figure -: Study Area Intersections with the Build Alternative I-/Trosper Road Interchange Justification Report Policy Point Page -

54 Policy Point Operational and Collision Analyses Intersection Table -: 0 AM Peak Hour Intersection Operations Intersection Control Mobility Standard No Build Alternative LOS (Delay) Worst V/C Ratio Build Alternative LOS (Delay) Worst V/C Ratio Trosper Littlerock Rd/ nd Ave Signal D D (0) 0. C () 0. I- SB Trosper Road Signal D D () 0. C () 0. I- NB Ramp/ th Trosper Rd Signal/RBT D D () 0. A () 0. Capitol Road Signal/RBT E C () 0. A () 0. Capitol Lee Street Signal D C () 0. B () 0. I- NB th Avenue RBT D A () 0. th Lee Street TWSC D B () 0.0. The Build Alternative would convert this intersection from an existing signal to a roundabout and alter the location of the northbound ramp termini.. The Build Alternative would add a second eastbound right turn lane for traffic heading south on Capitol Boulevard.. The Build Alternative would convert this signalized intersection to a roundabout. 0 0 PM Peak Hour Intersection Operating Performance Table - presents a comparison of 0 traffic operations during the PM peak hour for the No Build and Build Alternatives. There would be a slight improvement in delay on the west side of the freeway at the Trosper Road intersections with Littlerock Road/ nd Avenue and the I- southbound ramp termini resulting from improvements on the eastside of I-. A substantial improvement is expected at the 0 intersections of Trosper Road with th Avenue and Capitol Boulevard with operations improving from LOS C and D to LOS A for the two locations, respectively. Traffic operations at the new northbound offramp roundabout on th Avenue and at the intersection of th Avenue with Lee Street would operate at LOS A and B, respectively. Intersection operations worksheets are in Appendix E for the No Build Alternative and Appendix K for the Build Alternative. Intersection Table -: 0 PM Peak Hour Intersection Operations Intersection Control Mobility Standard No Build Alternative LOS (Delay) Worst V/C Ratio Build Alternative LOS (Delay) Worst V/C Ratio Trosper Littlerock Rd/ nd Ave Signal D D ().00 D () 0. I- SB Trosper Road Signal D D () 0. D () 0.0 I- NB Ramps/ th Trosper Rd Signal/RBT D C () 0. A () 0. Capitol Road Signal/RBT E D () 0.0 A () 0. Capitol Lee Street Signal D D (0) 0. C () 0. I- NB th Avenue RBT D A () 0. th Lee Street TWSC D B () 0. The Build Alternative would convert this intersection from an existing signal to a roundabout and alter the location of the northbound ramp termini. The Build Alternative would add a second eastbound right turn lane for traffic heading south on Capitol Boulevard. The Build Alternative would convert this signalized intersection to a roundabout. I-/Trosper Road Interchange Justification Report Policy Point Page -

55 Policy Point Operational and Collision Analyses Traffic Queuing Analysis Results As shown in Table - for the 0 No Build Alternative in the AM and PM peak hours, the southbound I- off-ramp queue is expected to back up onto the I- mainline. This queue would improve with the Build Alternative, where, in most cases, the anticipated queue would no longer extend back onto the I- mainline, primarily as a result of improved traffic movement across I- in the eastbound direction towards the proposed Capitol Boulevard/Trosper Road roundabout. The northbound ramp terminal is projected to experience queuing problems for eastbound traffic movements along Trosper Road in both the AM and PM peak hours with the No Build Alternative. Traffic queuing problems are also expected during the AM peak hour for westbound vehicles on Trosper Road. With the Build Alternative, including the addition of a roundabout at the relocated ramp termini intersection, no significant traffic queuing issues are anticipated at this location. Figure - illustrates projected traffic queues during the 0 PM peak hour for both the No Build and Build Alternatives. Traffic queuing issues at the intersection of Trosper Road with Capitol Boulevard are anticipated for most vehicle movements during the PM peak hour, with the more significant impacts occurring with northbound traffic. The impact of PM peak hour traffic queuing at this intersection can also be seen for the northbound through movement on Capitol Boulevard at Lee Street. The addition of a multilane roundabout at the intersection of Capitol Boulevard with Trosper Road with the Build Alternative would significantly reduce vehicle queuing, and no lane queue spillover impacts are anticipated Traffic queuing analysis worksheets are included in Appendix E for the No Build Alternative and Appendix K for the Build Alternative. 0 Lane Utilization As noted in the discussion of 0 existing peak hour traffic operations, unbalanced lane utilization for left-turn movements is a significant factor contributing to congestion and queue issues along northbound Capitol Boulevard and the southbound I- off-ramp. Poor lane utilization for the northbound Capitol Boulevard left-turn movement at Trosper Road would be resolved by the Build Alternative by providing a second access to northbound I- from the south. This improvement would allow traffic heading from Capitol Boulevard to northbound I- to divide between Trosper Road and Lee Street with both options providing a single left-turn lane from Capitol Boulevard. For the southbound I- off-ramp left-turn movement onto Trosper Road, projected future conditions analysis has assumed the existing unbalanced lane utilization would remain since no improvements would be made to that intersection. However, the design of the Build Alternative, which can accommodate heavy eastbound-to-southbound right turns from Trosper Road onto Capitol Boulevard, is expected to improve this lane imbalance. A select link analysis was conducted for the proposed roundabout at the I- northbound ramp termini to assess the effectiveness of the new th Avenue connection in attracting trips from the southbound off-ramp left-turn lanes to southbound Capitol Boulevard. The results of this analysis indicate less than percent of southbound left-turning traffic could be I-/Trosper Road Interchange Justification Report Policy Point Page -

56 Policy Point Operational and Collision Analyses Table -: 0 Peak Hour Traffic Queues No Build and Build Alternatives Vehicle No Build Alternative Build Alternative Intersection Storage AM Peak PM Peak AM Peak PM Peak Trosper Littlerock Rd/nd Ave Northbound Left 0 ft ft 0 ft ft ft Northbound Right 0 ft ft ft ft ft Southbound Left 0 ft ft ft 0 ft ft Southbound Thru/Right 0 ft ft ft ft ft Eastbound Left 00 ft ft 0 ft ft ft Westbound Left 00 ft ft ft ft ft I- SB Ramp/Tyee Trosper Road Northbound Left 00 ft ft ft ft ft Northbound Right 00 ft ft ft 00 ft ft Southbound Left 0 ft, ft, ft 0 ft 0ft Southbound Thru,00 ft,0 ft, ft ft ft Southbound Right 0 ft ft ft ft ft Eastbound Left 00 ft ft ft 0 ft ft Eastbound Right 0 ft ft ft ft 0 ft Westbound Left 0 ft 0 ft ft ft ft Westbound Thru,0 ft ft ft ft 0ft Westbound Thru/Right,0 ft 0 ft ft ft ft I- NB Ramps/ th Trosper Road Northbound Left,00 ft ft ft Northbound Right/(left/right) 00/00 ft ft ft ft ft Eastbound Thru 00 ft ft,0 ft ft ft Eastbound Thru/Right 00 ft ft ft ft ft Westbound Thru/Right 0 ft ft ft ft ft Capitol Trosper Road Northbound Left 00 ft ft ft Northbound Thru/Left 0 ft ft ft ft 0ft Northbound Thru/Right 0 ft ft ft 0 ft ft Southbound Thru >,000 ft ft 0 ft ft ft Southbound Left 00 ft ft ft ft ft Southbound Right 00 ft ft ft ft ft Eastbound Left / ft ft ft ft ft Eastbound Right 0 ft ft ft ft ft Capitol Lee Street Northbound Thru 0 ft ft ft ft ft Southbound Left 00 ft ft ft ft ft Southbound Thru/Right 0 ft ft ft 0 ft ft Eastbound Thru/Left 00 ft ft ft 0 ft ft Eastbound Right,00 ft ft ft ft ft I- NB Ramps at th Avenue Northbound Left 0 ft ft 0 ft Northbound Thru 0 ft ft ft Eastbound Left 00 ft ft 0 ft Southbound Right ft 0 ft 0 ft Southbound Thru ft ft ft th Avenue at Lee Street (TWSC) Southbound Left/Thru/Right 0 ft 0 ft ft Eastbound Left/Thru/Right 00 ft ft ft Westbound Left/Thru/Right 00 ft ft ft Bold results indicate locations where projected traffic queues may exceed available vehicle storage space. Northbound ramp intersection would be relocated to the proposed Ruby Road/ th Avenue intersection. The Build Alternative adds a second right turn lane for eastbound traffic. Reflects th percentile queues. I-/Trosper Road Interchange Justification Report Policy Point Page -

57 Policy Point Operational and Collision Analyses Figure -: I-/Trosper Road Comparison of 0 PM Peak Hour Traffic Queues I-/Trosper Road Interchange Justification Report Policy Point Page -

58 Policy Point Operational and Collision Analyses expected to use th Avenue. The development of this additional connection between Trosper Road and Capitol Boulevard to the south is not expected to cause any further imbalance in lane utilization. Construction of a roundabout at the Capitol Boulevard/Trosper Road intersection would provide a right-turn bypass lane for vehicles making an eastbound right-turn movement onto southbound Capitol Boulevard. However, should any vehicles wishing to make this rightturn movement fail to enter the curbside lane in time to use the bypass lane, they would still be able to make a right-turn movement by entering the roundabout. This creates a situation where both of the eastbound receiving lanes on Trosper Road that receive southbound off-ramp left turns from I- would provide the opportunity to turn right onto southbound Capitol Boulevard. This should help to balance existing and future No Build lane utilization problems. How do the Proposed Access Modifications Improve 00 Design Year Operations at the I-/Trosper Road Interchange? The discussion in this section compares future traffic projections and operational analysis results for both the No Build and Build Alternatives in the 00 AM and PM peak hours. Similar to the discussion for 0 and 0, the section documents merge/diverge analysis for the Trosper Road ramps onto and off of I-, ramp termini intersection operations, and operations at other nearby intersections. 00 Interchange Ramp Analysis A merge/diverge analysis was conducted for the projected 00 No Build and Build Alternatives which includes the relocation of the I- /northbound Trosper Road ramps south to a location generally on alignment with Ruby Street. Overall traffic volumes to and from I- with Build Alternative are expected to change very little from the No Build Alternative. This is because, while the Build Alternative results in significant reassignment of traffic across the city street system, the improvements do very little to change the volume of traffic using the interchange. The merge/diverge analysis results for the 00 AM and PM peak hours are presented in Table - and illustrated with projected PM peak hour volumes in Figure -. As indicated in the table, traffic during the AM peak hour would continue to operate at LOS D or better for all merge/diverge points. In the PM peak hour all of the merge/diverge points experience only decimal changes in density value. The southbound I- diverge point is projected to operate at LOS E for both the No Build and Build Alternatives. The merge/diverge analysis worksheets are included in Appendix F for the No Build Alternative and Appendix L for the Build Alternative. I-/Trosper Road Interchange Justification Report Policy Point Page -

59 Policy Point Operational and Collision Analyses Figure -: 00 PM Peak Hour Comparison of Mainline Volumes and Operations I-/Trosper Road Interchange Justification Report Policy Point Page -

60 Policy Point Operational and Collision Analyses Merge/Diverge Point No Build Alternative AM Peak Hour Build Alternative No Build Alternative PM Peak Hour Build Alternative Northbound I- Diverge Point C (.) D (.) C (.) C (.) Northbound I- Merge Point C (.) C (.) D (.) D (.) Southbound I- Diverge Point D (.) D (.0) E (.) E (.) Southbound I- Merge Point B (.) B (.) C (0.) C (0.) Bold Table -: Projected 00 Merge/Diverge Analysis Results results exceed adopted performance standard AM Peak Hour Intersection Operating Performance By the 00 planning horizon year, the projected traffic volume increase with the No Build Alternative would result in failing operations at two locations in the study area during the AM peak hour. The intersection of Trosper Road with the I- southbound ramps is expected to operate at LOS E, while the intersection of Trosper Road with Capitol Boulevard is expected to operate at LOS F with multiple failing movements. Operations at 0 Trosper Road/Capitol Boulevard would result in frequent signal cycle failures with queues building throughout the peak period. As illustrated in Table - with the improvements proposed in the Build Alternative, operations at the intersection of Trosper Road with the I- southbound ramps are expected to remain at LOS E with a slight improvement in average vehicle delay. Operations at the intersection of Trosper Road with Capitol Boulevard are expected to improve substantially from LOS F to LOS A. Intersection Table -: 00 AM Peak Hour Intersection Operations Intersection Control Mobility Standard No Build Alternative LOS (Delay) Worst V/C Ratio Build Alternative LOS (Delay) Worst V/C Ratio Trosper Littlerock Rd/ nd Ave Signal D D () 0. D () 0. I- SB Trosper Road Signal D E ().0 E ().0 I- NB Ramps/ th Trosper Rd Signal/RBT D D (0) 0. A () 0. Capitol Road Signal/RBT E F ().0 A () 0. Capitol Lee Street Signal D D (). C () 0. I- NB th Avenue RBT D A () 0. th Lee Street AWSC D B () 0. Bold results exceed adopted intersection operating performance standard. The Build Alternative would convert this intersection from an existing signal to a roundabout and alter the location of the northbound ramp termini. The Build Alternative would add a second eastbound right turn lane for traffic heading south on Capitol Boulevard. The Build Alternative would convert this signalized intersection to a roundabout. The Build Alternative would convert the original two-way stop control signage to all-way stop control to address extensive PM peak hour southbound left turn queues after 0. I-/Trosper Road Interchange Justification Report Policy Point Page -0

61 Policy Point Operational and Collision Analyses 0 00 PM Peak Hour Intersection Operating Performance As shown in Table -0, PM peak hour No Build Alternative traffic operations are expected to fail at three intersections along Trosper Road - Littlerock Road/ nd Avenue (expected to operate at LOS E), the I- southbound ramps and Capitol Boulevard (both expected to operate at LOS F). Operations at Trosper Road and Capitol Boulevard would see excessive queuing and delay with spillback effects on both streets. The double eastbound-to-southbound right-turn lane in the Build Alternative effectively corrects the queuing problem on eastbound Trosper Road. Traffic operations at the intersection of Trosper Road with Littlerock Road/ nd Avenue are expected to improve to LOS D with the Build Alternative. Intersection Table -0: 00 PM Peak Hour Intersection Operations Intersection Control Mobility Standard No Build Alternative LOS (Delay) Worst V/C Ratio Build Alternative LOS (Delay) Worst V/C Ratio Trosper Littlerock Rd/ nd Ave Signal D E () 0. D () 0. I- SB Trosper Road Signal D F (). F (). I- NB Ramps/ th Trosper Rd Signal/TWSC D C () 0. A () 0. Capitol Road Signal/RBT E F ().0 A () 0. Capitol Lee Street Signal D D ().0 D (0) 0. I- NB th Avenue RBT D A () 0. th Lee Street AWSC D D () 0. Bold results exceed adopted intersection operating performance standard. The Build Alternative would convert this intersection from an existing signal to a roundabout and alter the location of the northbound ramp termini. The Build Alternative would add a second eastbound right turn lane for traffic heading south on Capitol Boulevard. The Build Alternative would convert this signalized intersection to a roundabout. The Build Alternative would convert the original two-way stop control signage to all-way stop control to address extensive PM peak hour southbound left turn queues after The initial design concept for the intersection of the new th Avenue with Lee Street would include two-way stop control on th Avenue, allowing Lee Street traffic to move freely. In 0, the southbound stop-controlled movement on th Avenue would operate at LOS B during both the AM and PM peak hours. By 0, it is expected that the southbound left turn movement would fall to LOS E during the PM peak hour with a traffic queue approaching 0 feet. There are multiple ways to address this operational issue including: 0 Installation of all-way stop-control that would result in LOS B for the southbound left movement with queues below feet. Construction of th extension and T extension would reroute traffic and could allow for stop-control along Lee Street. Consideration of traffic signal installation; however, the volume warrants are not expected to be met until 00. I-/Trosper Road Interchange Justification Report Policy Point Page -

62 Policy Point Operational and Collision Analyses 0 By the 00 PM peak hour, two way stopcontrol on th Avenue would result in an LOS F with a queue exceeding feet in the PM peak hour. This queue would interfere with smooth traffic operations at the intersection of the proposed I- northbound off-ramp at th Avenue. Installation of all-way stop control at the th Avenue/Lee Street intersection would improve 00 PM peak hour operations to LOS C with approximately 00 feet of traffic queuing along Lee Street. Traffic signal warrants would be met around 00 and a signal would operate well for both peak hours Traffic Queuing Analysis Results A queuing analysis was performed for the AM and PM peak hours for both the No Build and this Build Alternatives for 00. The results of this analysis are presented in Table -. Key roadway locations where queue analysis results are being reported are shown in Figure -. For both the AM and PM peak hour, the southbound I- off-ramp queue is expected to back up onto the I- mainline in the projected 00 No Build Alternative. This queue is expected to improve with the Build Alternative. With the exception of the Table -: 00 Peak Hour Traffic Queues No Build and Build Alternatives Vehicle No Build Alternative Build Alternative Intersection Storage AM Peak PM Peak AM Peak PM Peak Trosper Littlerock Rd/nd Ave Northbound Left 0 ft ft ft 0 ft ft Northbound Right 0 ft 0 ft, ft ft 0 ft Southbound Left 0 ft ft 0 ft ft ft Southbound Right 0 ft ft ft ft ft Eastbound Left 00 ft ft ft ft ft Westbound Left 00 ft ft ft ft ft I- SB Ramp/Tyee Trosper Road Northbound Left 00 ft ft ft 0 ft ft Northbound Right 00 ft ft ft 0 ft ft Southbound Left 0 ft,0 ft, ft ft, ft Southbound Thru,00 ft, ft, ft ft, ft Southbound Right 0 ft 0 ft ft ft 0ft Eastbound Left 00 ft ft ft ft ft Eastbound Right 0 ft ft ft ft ft Westbound Left 0 ft ft ft ft ft Westbound Thru,0 ft ft ft ft ft Westbound Thru/Right,0 ft ft ft ft ft I- NB Ramps/ th Trosper Road Northbound Left,00 ft 0 ft 00 ft Northbound Right/(left/right) 00/00 ft ft ft 0 ft 0 ft Eastbound Thru 00 ft ft ft ft 0 ft Eastbound Thru/Right 00 ft ft ft ft 0 ft Westbound Thru/Right 0 ft ft ft 0 ft ft Capitol Trosper Road Northbound Left 00 ft ft ft Northbound Thru/Left 0 ft ft ft ft ft Northbound Thru/Right 0 ft ft ft ft 0 ft Southbound Thru >,000 ft ft ft ft ft Southbound Left 00 ft ft 0 ft ft Southbound Right 00 ft ft ft ft 0 ft Eastbound Left / ft ft 0 ft ft ft Eastbound Right 0 ft 0 ft ft ft ft I-/Trosper Road Interchange Justification Report Policy Point Page -

63 Policy Point Operational and Collision Analyses Table -: 00 Peak Hour Traffic Queues No Build and Build Alternatives Continued Vehicle No Build Alternative Build Alternative Intersection Storage AM Peak PM Peak AM Peak PM Peak Capitol Lee Street Northbound Thru 0 ft 0 ft, ft ft ft Southbound Left 00 ft ft ft ft 0 ft Southbound Thru/Right 0 ft ft ft ft ft Eastbound Left 00 ft 0 ft ft ft ft Eastbound Right/Thru,00 ft, ft, ft ft ft I- NB Ramps at th Avenue Northbound Left 0 ft ft ft Northbound Thru 0 ft ft ft Eastbound Left 00 ft ft ft Southbound Right ft 0 ft 0 ft Southbound Thru ft ft ft th Avenue at Lee Street (AWSC) Southbound Left/Thru/Right 0 ft ft 0 ft Eastbound Left/Thru/Right 00 ft ft ft Westbound Left/Thru/Right 00 ft 0 ft 0 ft Bold results indicate locations where projected traffic queues may exceed available vehicle storage space. Northbound ramp intersection would be relocated to the proposed Ruby Road/ th Avenue intersection. The Build Alternative adds a second right turn lane for eastbound traffic. Reflects th percentile queues. 0 0 southbound left, this queue should be reduced such that it would no longer extend back onto mainline I-. However, westbound through traffic queues at this intersection are expected to increase from approximately feet with the No Build Alternative to approximately, feet with the Build Alternative. This impact is an anticipated result of the change from a traffic signal-controlled intersection at Trosper Road/Capitol Boulevard to a multi-lane roundabout which no longer meters traffic flow onto westbound Trosper Road. Heavy congestion at the traffic signal effectively meters traffic heading west on Trosper Road towards the I- southbound ramp intersection. With significantly improved traffic operations at the roundabout, more traffic can approach the I- southbound intersection and the westbound queue gets longer. This queue would extend through the proposed 0 0 roundabout at Trosper Road/ th Avenue and reach the Capitol Boulevard/Trosper Road roundabout. With completion of the City s new Transportation Plan, it is expected that a future improvement to this intersection will be developed. The northbound ramp terminal is not projected to see any queuing issues with the Build Alternative, when the existing northbound I- off-ramp is converted to a city street ( th Avenue). The new intersection of th Avenue with Trosper Road would provide a single lane approach for th Avenue at the proposed roundabout. The northbound queue at this new repurposed intersection is not expected to extend back to the I- northbound off-ramp roundabout on th Avenue. The queue analysis worksheets are included in Appendix F for the No Build Alternative and Appendix L for the Build Alternative I-/Trosper Road Interchange Justification Report Policy Point Page -

64 Policy Point Operational and Collision Analyses Figure -: I-/Trosper Road Comparison of 00 PM Peak Hour Traffic Queues I-/Trosper Road Interchange Justification Report Policy Point Page -

65 Policy Point Operational and Collision Analyses Lane Utilization As noted in the discussion of 0 existing and 0 no build peak hour traffic operations, unbalanced lane utilization for left-turn movements is a significant factor contributing to congestion and queue issues along both northbound Capitol Boulevard and the southbound I- off-ramp. The poor lane utilization for the northbound Capitol Boulevard left-turn movement at Trosper Road would be resolved by the Build Alternative in all analysis years by providing a second access to northbound I- from the south. This improvement would allow traffic heading from Capitol Boulevard to northbound I- to divide between Trosper Road and Lee Street, with both options providing a single left-turn lane from Capitol Boulevard. See discussion under 0 Lane Utilization analysis for further discussion of benefits associated with the Build Alternative. 0 0 How would the Proposed Build Alternative affect the Connections with Local Roads and Intersections? The redesign of the I- interchanges at Trosper Road would affect local travel patterns and change how drivers access I- from the local street system. However, as indicated in Figure - and Figure -, no significant change in traffic volumes entering or existing I- at Trosper Road is expected. Table - presents a summary of projected 0 and 00 AM and PM peak hour volumes on Trosper Road to the west of the I- ramps, and on Capitol Boulevard both north and south of Trosper Road. Review of this data shows the minimal changes in regionally-significant traffic volumes that are expected as a result of the Build Alternative. As shown in the table, the difference in total two-way traffic at each location and for each time period is expected to be less than 00 vehicles. Table -: 0 and 00 Two-way Volume on Local Streets-No Build Alternative vs. Build Alternative Location Capitol Boulevard north of Trosper Road Capitol Boulevard south of Lee Street Trosper Road west of NB Ramps 0 No Build AM Peak Hour 0 Build 00 No Build 00 Build 0 No Build PM Peak Hour 0 Build 00 No Build 00 Build,0,0,0,0,00,0,0,0,0,0,0,0,0,0,00,0,0,0,0,00,0,0,0,0 Summary of Traffic Operational Impacts The City of Tumwater recently completed the CBCP that identifies a preferred development strategy and roadway improvement plan for the South Capitol Boulevard area from Trosper 0 Road to Israel Road. The intersection of Capitol Boulevard/Trosper Road was identified as a critical location within the corridor. A valuebased alternatives analysis process was used to identify the recommended improvements to address deficiencies at the intersection. I-/Trosper Road Interchange Justification Report Policy Point Page -

66 Policy Point Operational and Collision Analyses The alternatives analysis included an evaluation of operational performance and identified how each of the alternatives potentially impacted the operations of Interstate (I-) and the Trosper Road interchange area. This alternatives analysis led to identification of a preferred Build Alternative. Comparison of traffic operational impacts associated with the No Build and Build Alternatives highlighted the following: Ramp merge/diverge analysis was performed for each ramp in the 0 and 00 AM and PM peak hours. The results indicate very little change is expected between the No Build and Build Alternatives. This is due to the minor change in volumes along I- with the two alternatives, and for the Trosper Road ramps in both directions. All locations would operate at acceptable levels of service with the exception of the southbound I- diverge point to Trosper Road (LOS E in 00) for both the No Build and Build Alternatives. There are currently two significant lane imbalances that contribute to the congestion in the Trosper Road interchange area, including the Capitol Boulevard/Trosper Road intersection. The northbound left-turn lane utilization at the Capitol Boulevard/Trosper Road intersection would be resolved by the Build Alternative that includes a modified I- northbound off-ramp and a multi-lane roundabout at the Trosper Road/Capitol Boulevard intersection. The southbound left-turn lane utilization at the intersection of the I southbound ramps with Trosper Road would be improved by building the Capitol Boulevard/Trosper Road roundabout. Level of service, delay and queuing analysis was performed for AM and PM peak hours with the No Build and Build Alternatives. Analysis included both the 0 opening year and the 00 longrange planning horizon year. o In 0, all intersections would operate at acceptable levels of service with both alternatives. However, extensive traffic queuing would be experienced with the No Build Alternative along Trosper Road, at the two freeway ramp intersections, and along Capitol Boulevard at or in the vicinity of Trosper Road. With the Build Alternative, most traffic queuing problems would be resolved or substantively reduced. o In 00, the intersection of Trosper Road with the I- southbound ramps would fail during both the AM and PM peak hours with either the No Build or Build Alternatives. However, traffic queuing at this location would be much more extensive with the No Build Alternative, impacting southbound through traffic on the I- mainline. With the Build Alternative, this queuing would be substantially reduced. AM and PM peak hour traffic operations at the intersection of Trosper Road with Capitol Boulevard are also expected to fail with the No Build Alternative I-/Trosper Road Interchange Justification Report Policy Point Page -

67 0 0 0 and queuing along Trosper Road and Capitol Boulevard would be significant. The Build Alternative would improve operations at the Trosper Road/Capitol Boulevard intersection to LOS A and most queue spillback impacts would be eliminated. Operations at the I- northbound ramp termini intersection would also be substantially improved with the Build Alternative. What is the Existing Crash Experience in the Project Area? As noted at the beginning of this chapter, the crash experience and safety analysis included in Policy Point was addressed extensively in earlier studies. Crash data and analysis has been updated as part of this IJR to reflect the most recently available information. This section includes a discussion of: Crash data resources and analysis methods Crash history at and in the vicinity of the I- interchange with Trosper Road including interchange ramps and ramp termini intersections Crash history at other project study area intersections on the local street system Predictive analysis of expected crashes in 00 and 00 for both the No Build and Build Alternatives Crash analysis is included in Appendix M. 0 0 Policy Point Operational and Collision Analyses What was the Process used to Evaluate Crashes in the Project Area? What Locations were Studied? The analysis is this section focuses the I- /Trosper Road interchange including on- and off-ramps and ramp termini intersections. Analysis of recent crash experience, as well as predictions of future crashes for the No Build Alternative, are based on the existing configuration of the interchange. Future conditions analysis with the Build Alternative includes an assessment of the new northbound off-ramp and ramp termini intersection. Intersections for which crash safety analysis was conducted include the same locations for which traffic operations analysis was conducted. These locations are shown in Figure -. What Information was Collected and Evaluated? Crash data was obtained and compiled for a five-year period between January, 00 and December, 0. This information was obtained from the Washington State Department of Transportation s Crash Data and Reporting Branch. Under Section 0 of Title of the United States Code, any collision data furnished is prohibited from use in any litigation against state, tribe or local government that involves the location(s) mentioned in the collision data. 0 What Analysis Methods and Tools Were Used? A statistical analysis was conducted of the - year traffic crash data in the study area to identify typical crash patterns and magnitude. Data was evaluated separately for the I- /Trosper Road ramps and ramp termini intersections, and for other project study area intersections. Data analysis included identification of: I-/Trosper Road Interchange Justification Report Policy Point Page -

68 Policy Point Operational and Collision Analyses Crash location and frequency Crash type (i.e., rear-end, sideswipe, turning, etc.) What is the Existing Crash Experience in the Project Area? Five Year Crash Summary Severity of crashes (i.e. fatal, serious 0 Using data from January 00 through injury, evident injury, possible injury December 0, a five-year crash analysis was and non-injury or property damage conducted for the I- ramps at Trosper Road only) and the key intersections in the study area. Contributing causes of crashes Analysis included a review of existing crash In addition to the statistical assessment of rates and location, severity, type, and crashes in the vicinity of the I-/Trosper Road contributing factors. interchange, crash rate calculations were As illustrated in Table - during this five-year developed and reviewed for each intersection. period there were reported crashes on the For crashes associated with the interchange I- ramps to/from Trosper Road, and at study ramps and ramp termini an assessment was 0 area intersections. Approximately percent made of crash history using the predictive occurred on the I- northbound and features of AASHTO s HSM Freeway Predictive southbound ramps, with percent occurring Model based on the ISATe application at intersections of the I- northbound and spreadsheet. Expected crashes were estimated southbound ramps with Trosper Road (ramp for the interchange ramps and ramp termini termini intersections). percent of the crashes intersections for 00 and 00 with both the in the study area occurred at the remaining No Build and Build Alternatives. A comparison three intersections including Trosper Road with of expected crashes with and without the Littlerock Road/ nd Avenue and with Capitol Project provides an indication of potential safety-related benefits or impacts Table -: 00-0 Crashes and Crash Rates by Location associated with the proposed 00 to Average action. Ramps and Study Area Street 0 Annual Crash Rate Boulevard, and Capitol Boulevard Intersections Crashes Crashes per MEV * with Lee Street. I- Interchange Ramps I- NB On-Ramp. -- The intersection of the I- I- NB On-Ramp (slip).0 -- southbound ramps with Trosper I- NB Off-Ramp Road experienced the highest I- SB On-Ramp I- NB Off-Ramp. -- number of annual crashes of any I- Ramp Termini Intersections location in the study area (nearly I- NB Ramp/Trosper Road. 0. per year). The crash rate at this I- SB Ramp/Trosper Road..0 location exceeds.00 per million Other Intersections entering vehicles and indicates that Trosper Road/Littlerock/nd. 0. Trosper Road/Capitol Blvd. 0. consideration should be given to Capitol Blvd/Lee Street.0 0. crash mitigation at this location. All Crashes. While this intersection would not *MEV = Million Entering Vehicles be improved by the proposed I-/Trosper Road Interchange Justification Report Policy Point Page -

69 Policy Point Operational and Collision Analyses project, the Tumwater Transportation Plan does recognize the need for future improvements at this location which could address both future operating performance and safety. Closely associated with the I- southbound ramp termini location is the intersection of Trosper Road with Littlerock Road/ nd Avenue. This intersection is experiencing a crash rate of 0. per million entering vehicles which is also indicative of a potential safety concern. The intersection of Capitol Boulevard with Lee Street is experiencing a crash rate of 0. per million entering vehicles and this intersection would be impacted by the proposed Build Alternative. Crashes at this location are dominated by rear end collisions which are indicative of significant traffic queuing issues associated with congestion at the Trosper Road/Capitol Boulevard intersection. Three crashes at this location involved pedestrians, all of whom were injured. Traffic congestion and queuing improvements associated with the Build Alternative are expected to benefit the risk of crashes at the Capitol Boulevard/Lee Street intersection. 0 0 The safety benefits of the Build Alternative are further discussed later in this section. The remainder of the discussion about recent crash experience focuses solely on the I-/Trosper Road ramps and ramp termini intersections including a review of crash severity, types of crashes and contributing circumstances. Crash Severity As shown in Table -, a summary of five-year crash experience for the I-/Trosper Road ramps and ramp termini intersections has been prepared by severity. There were no crashes involving fatalities or serious injuries in the interchange area during the analysis period. There were three crashes with evident (nondisabling) injuries, and (or percent of all crashes) with possible injuries (including momentary unconsciousness and/or claim of injuries not evident, limping, complaint of pain, nausea, hysteria, etc.). The majority of crashes in the interchange area (0 percent) involved only property damage. Figure - presents a graphic illustration of interchange area crashes by severity. Table -: 00-0 I-/Trosper Road Interchange Area Crash Severity Severity of Collisions Ramps and Cross Streets 0 00 to 0 Collisions Average Annual Collisions Percentage of Crashes Fatal & Serious Injuries 0 0 0% Evident Injuries 0..% Possible Injuries..% Property Damage Only 0.% Unknown 0..% All Collisions. 00% I-/Trosper Road Interchange Justification Report Policy Point Page -

70 Policy Point Operational and Collision Analyses Figure -: I-/Trosper Road Interchange Area Crashes by Severity Types of I-/Trosper Road Interchange Area Both of these types of crashes are heavily Crashes indicative of congestion and unbalanced traffic As shown in Figure -, approximately 0 movement by lane. About percent of the percent of crashes in the I-/Trosper Road crashes involve entering at an angle, with interchange area are rear end collisions, and percent hitting fixed objects, such as a nearly percent are sideswipe collisions. concrete barrier or a ditch. Figure -: I-/Trosper Road Interchange Area Crashes by Type I-/Trosper Road Interchange Justification Report Policy Point Page -0

71 Policy Point Operational and Collision Analyses Contributing Circumstances for I-/Trosper Road Interchange Area Crashes As shown on Figure - and based on existing crash data, there are several circumstances that contribute to collisions in the vicinity of the I- 0 /Trosper Road interchange. Inattention and following too closely contribute to more than half of all crashes ( percent). Exceeding reasonable speeds contributed to percent of all crashes and failure to grant right-of-way resulted in percent of crashes. Figure -: I-/Trosper Road Interchange Area Crashes by Contributing Circumstances How is Crash Frequency Expected to Change over the Planning Period? A number of model runs based on the Enhanced Interchange Safety Analysis Tool (ISATe) were used to predict the safety performance of the Build Alternative in 0 and 00, and to compare it to future baseline conditions (i.e., the No Build Alternative) for these same analysis years. These models were developed based on the FHWA Highway Safety Manual. The 0 base model was created and calibrated to reflect existing crash experience at the I-/Trosper Road interchange using the traffic collision data from 00 through 0. The model uses geometric and Average Daily 0 0 Trip (ADT) data for the ramps and ramp termini intersections, and considers roadside features such as rumble bars and guardrails. Table - shows a comparison between expected crashes based on data recorded in the field and the predicted number of crashes that were estimated by the ISATe model. These predicted crashes represent likely conditions for a typical interchange facility with characteristics similar to I-/Trosper. As shown for 0 conditions in the table, the ISATe model predicts nearly 0 percent more crashes than actually occurred. Based on these results, the I-/Trosper interchange appears to be operating with fewer crashes than would be expected for a similar interchange. This finding is particularly significant with respect to I-/Trosper Road Interchange Justification Report Policy Point Page -

72 Policy Point Operational and Collision Analyses 0 0 existing fatal or injury collisions which are actually substantially lower than predicted. Once the data was collected and entered into the spreadsheet-based program and compared to existing crash experience, the ISATe tool was used to estimate the frequency and severity of crashes expected in the study area for future analysis years. The tool is also used to predict types of crashes and whether one or multiple vehicles would likely be involved. One of the constraints of the ISATe tool is that it doesn t recognize roundabouts as a means of controlling traffic at an intersection. The model does recognize traffic signal or stop sign control. Thus, in situations where planned improvements include reconfiguring an intersection to a roundabout, analysis should initially assume that a traffic signal would be in place and then the results should be modified to reflect the safety and operational improvements associated with a roundabout. This is accomplished by applying a Crash Modification Factor (CMF) to the crash predictions based on the traffic signal. In this study, the intersection of the northbound offramp at th Avenue was initially assumed to include a traffic signal. To estimate 0 and predicted crashes with the proposed roundabout, a CMF of 0. was applied to the injury and fatal crash predictions of signalized control to derive the crash predictions reported in Table -. As reflected in Table -, the annual number of ramp and ramp termini intersection crashes with the 0 No Build Alternative is expected to be approximately. With the 0 Build Alternative, total crashes are predicted to decrease to slightly more than per year. As shown in Figure -, traffic volumes entering and leaving the interchange area are expected to remain relatively consistent, while localized traffic distribution is expected to change, resulting in positive safety improvements. The conversion of the existing I- ramp termini to a roundabout will also help improve safety. For 00, 0 crashes per year are predicted to occur with the No Build Alternative, which compares to fewer than crashes per year predicted with the 00 Build Alternative. Summaries of the ISATe model outputs for the No Build and Build Alternatives in 0 and 00 are contained in Appendix M. I-/Trosper Road Interchange Justification Report Policy Point Page -

73 Policy Point Operational and Collision Analyses Study Year/Scenario Table -: Annual Predicted Crashes for the I-/Trosper Road Interchange Area Annual Crashes at Ramps and Ramp Termini Intersections Fatal Serious Injury Evident Injury Possible Injury Property Damage Only 0 Existing (Expected) Multiple Vehicles Single Vehicles Total Existing (Predicted) Multiple Vehicles Single Vehicles Total Actual over Predicted 0 (0.) (.) (.) (.) (.) 0 No Build Alternative Multiple Vehicles Single Vehicles Total Build Alternative Multiple Vehicles Single Vehicles Total Build over No Build Alternatives 0 (0.) (.) (.) (.0) (.) 00 No Build Alternative Multiple Vehicles Single Vehicles Total Build Alternative Multiple Vehicles Single Vehicles Total Build over No Build Alternatives 0 (0.) (.) (.) (0.) (.) Note: Analysis in this table is based on 00-0 crash data, 0 traffic volumes, and the predictive features of AASHTO s HSM Freeway Predictive Model using the ISATe application spreadsheet. Note : The analysis of expected crashes is based on existing crash data at the I- northbound/trosper Road interchange, while predicted crashes represent likely crash experience based on comparable or similar interchanges. Where expected crashes are less than predicted crashes an intersection is said to be operating better than what might be expected. Total I-/Trosper Road Interchange Justification Report Policy Point Page -

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75 Policy Point Access Connections and Design. POLICY POINT # ACCESS CONNECTIONS AND DESIGN Introduction Policy Point addresses how the proposed access modifications at the I-/Trosper Road interchange are fully directional, connected to public roads, and designed to meet identified performance standards. The Build Alternative addressed in this IJR is described in Policy Point. Will the I-/Trosper Road Project Provide a Fully Directional Interchange Connected to Public Roads? Fully directional interchanges provide access between a public street and a limited access highway in all directions. This includes providing both on-ramps and off-ramps in both directions of travel. Interchanges that are not fully directional lack one or more of these movements. The proposed modifications to the interchange of I- with Trosper Road will continue to provide fully directional access that is connected to the public street system via Trosper Road. These modifications are illustrated in Figure -. What Modifications would be Made to the I- Mainline? No modifications would be made to the I- mainline or to the existing interchange ramp gore points. The radius of the northbound loop on-ramp will be smaller with the Build Alternative than existing. The new ramp design speed will be mph. Evaluation of acceleration lane length to accommodate the merge with 0 mph mainline design speed was conducted and determined to be adequate. What are the Proposed Trosper Road Interchange Modifications? The project includes the following elements: Relocate the I- northbound off-ramp to intersect a new north/south road ( th Avenue) with a single lane roundabout at approximately Ruby Street Construct new th Avenue from Trosper Road to Lee Street Construct a two lane roundabout at the intersection of Capitol Boulevard with Trosper Road to increase capacity at this existing intersection Construct a two lane roundabout at the new th Avenue at Trosper Road intersection Construct localized access streets by extending Trosper Road east of Capitol Boulevard and then south to Linda Street The modified northbound off-ramp and other improvements will be designed based on the latest traffic analysis and WSDOT or appropriate local agency design criteria. Each of these improvements is described in greater detail on the following pages. Existing access to/from the I- southbound ramps will be maintained as currently configured. I-/Trosper Road Interchange Justification Report Policy Point Page -

76 Policy Point Access Connections and Design Figure -: Conceptual Layout for I-/Trosper Northbound Off-ramp and Capitol/Trosper Intersection I-/Trosper Road Interchange Justification Report Policy Point Page -

77 Policy Point Access Connections and Design Relocate Northbound I- Ramps to a Roundabout at Ruby Street This improvement entails development of a roundabout at the relocated terminus for the I- /Trosper Road northbound off-ramp. The roundabout would intersect a new north/south street ( th Avenue) at a location generally aligned with Ruby Street. Ruby Street currently provides east/west local street access east of Capitol Boulevard, north of and parallel to Lee Street. From this roundabout it would be possible to travel north to where traffic would be able to access Trosper Road at the proposed two lane roundabout. Traffic wishing to head northbound on I- from the east along Trosper Road would continue to use the existing northbound on-ramp on the north side of Trosper Road. Traffic desiring to head northbound on I- from the west would use the right-most travel lane on eastbound Trosper Road, and make a right turn movement onto th Avenue. Shortly after accessing th Avenue a right-turn pocket will form, providing access to the I- northbound on-ramp, which would travel under the Trosper Road bridge and merge with the westbound-to-northbound ramp before entering the freeway mainline at the existing merge location. It would also be possible to head south from the ramp termini roundabout intersection to connect with Lee Street. From this point, traffic could turn right to reach local destinations south of Trosper Road on the west side of Capitol Boulevard. Traffic could also turn left onto Lee Street to reach Capitol Boulevard and then head south. This improvement will require coordination/ approval by WSDOT for realignment of the ramps and changes to access limits. The possible future addition of an east leg to this roundabout would access businesses in the area between th Avenue, Capitol Boulevard, Trosper Road, and Lee Street. This additional connection would significantly benefit local property access and traffic circulation in this congested commercial area. Construct New th Avenue from Trosper Road to Lee Street As shown in Figure -, this improvement includes construction of a new north/south street (th Avenue) between Trosper Road and Lee Street. This street would be located and designed to accommodate the realigned I- /Trosper Road northbound on and off-ramps which would terminate at a new roundabout as described above. th Avenue would include a single travel lane in both directions except for northbound traffic between Lee Street and the ramp termini roundabout. Two travel lanes would be provided along this roadway segment including the roundabout one to accommodate northbound traffic heading to Trosper Road (the outside lane) and the other to serve traffic heading to the I- northbound on-ramp (the inside lane). One northbound travel lane would be provided north of the roundabout. A single southbound travel lane would be provided for the movement between Trosper Road and Lee Street, with a right-turn pocket being provided as th Avenue approaches the relocated I- ramps roundabout. It is anticipated that northbound traffic exiting I- will use th Avenue in both directions. It is also anticipated that eastbound Trosper Road traffic destined to northbound I- will use southbound th Avenue to reach the freeway I-/Trosper Road Interchange Justification Report Policy Point Page -

78 Policy Point Access Connections and Design on-ramp. This on-ramp lane would be accessed via a right-turn pocket and bypass the circulating lanes in the roundabout. 0 signalized intersection and is expected to perform well through the 00 planning horizon year Northbound traffic on Capitol Boulevard south of Trosper Road destined for I- northbound would have the choice of either turning left at Lee Street and then reaching the on-ramp via th Avenue, or by turning left at Trosper Road and using the existing northbound on-ramp. Analysis indicates that the new access via th Avenue would pull a significant volume of traffic away from the Capitol Boulevard/Trosper Road intersection, thus reducing traffic congestion and conflicts at this location. Two-lane Roundabout at Capitol Boulevard/ Trosper Road The diversion of traffic provided by the new th Avenue and Ruby Street roundabout allows for construction of a two-lane roundabout at the intersection of Trosper Road with Capitol Boulevard. This improvement is shown in Figure -. In addition to the two circulating lanes, the roundabout would also provide bypass lanes to accommodate existing and heavy traffic movements. One bypass lane would serve southbound-to-westbound traffic and the other would serve eastbound-to-southbound traffic. Constructing a multilane roundabout provides several specific advantages: The multilane roundabout would accommodate U-turning traffic along Capitol Boulevard and Trosper Road Constructing a roundabout provides a gateway to the Capitol Boulevard corridor and improves conditions for pedestrians and cyclists. The roundabout also provides enhanced safety in comparison to a Local Access Streets East of Capitol Boulevard These improvements are illustrated in Figure - and would provide added accessibility for businesses located on the east side of Capitol Boulevard. Improvements would include: Extending Trosper Road east of Capitol Boulevard by enhancing the fourth (easterly) leg to the Trosper Road/Capitol Boulevard multilane roundabout. Improving accessibility for traffic along the existing segment of Linda Street east of Capitol Boulevard and south of Trosper Road. With the multilane roundabout, access to/from Capitol Boulevard at Linda Street would be limited to right-in/right-out movements. Adding a new north/south road east of and parallel to Capitol Boulevard between the Trosper Road extension and Linda Street. How do the Proposed Access Revisions fit into the Larger Capitol Boulevard Corridor Plan project? The foregoing improvements are all part of a two-phased program to address existing and projected traffic congestion in the vicinity of the I-/Trosper Road northbound ramps. These improvements are part of larger strategy to enhance multimodal mobility and accessibility along the entire Capitol Boulevard corridor from Trosper Road to Israel Road. I-/Trosper Road Interchange Justification Report Policy Point Page -

79 Policy Point Access Connections and Design 0 Collectively, the foregoing improvements are part of a larger Capitol Boulevard improvement program. Additional improvements that would be built during later project phases are illustrated in Figure - and include: Extension of th Avenue from Lee Street to T Street. Extension of the north/south street east of Capitol Boulevard between Trosper Road and Linda Street further south to Lee Street. Intersection improvements including roundabouts at the intersections of Capitol Boulevard with T Street X Street and Dennis Street. 0 0 Extend the North/South Street east of Capitol Boulevard from Linda Street further south to Lee Street This street extension would provide improved localized accessibility in the area east of Capitol Boulevard and south of Trosper Road. It will be important to ensure that this street does not become a cut-through route for traffic looking to avoid northbound congestion at the Capitol Boulevard/Trosper Road intersection. Intersection improvements on Capitol Boulevard south of Lee Street Roundabouts would be built at Trosper Road, T Street, X Street, and Dennis Street and existing signals would remain at Israel Road and Tumwater Boulevard. 0 These improvements are described below. Extend th Avenue from Lee Street to T Street The Capitol Boulevard/T Street intersection is identified as a future roundabout in the Corridor Plan. Extending th Avenue south to T Street allows for vehicles to move left from Capitol Boulevard at a controlled intersection to reach the I- on-ramp at Ruby Street. This would allow for the elimination of a controlled intersection at Lee Street (currently a traffic signal) and provide balanced controlled intersection spacing between Trosper Road and Israel Road (about ¼ mile spacing). 0 Will the Modified and New Interchanges be Spaced According to Guidelines? Per the WSDOT Design Manual, interchange spacing is one mile in urban areas and is measured between the overpass bridges of adjacent interchanges. Interchange spacing with the project is: Tumwater Boulevard to Trosper Road. miles Trosper Road to US0/Deschutes Way ramp. miles 0 This extension also provides better north-south connectivity parallel to Capitol Boulevard and allows for more access control on Capitol Boulevard. This improvement would likely be phased to occur with redevelopment of the WSDOT site and construction of the T Street roundabout. It should be noted that there is a northbound off-ramp to Deschutes Way (Exit 0) between the Trosper Road interchange and the ramp to US 0 but there is no full interchange. I-/Trosper Road Interchange Justification Report Policy Point Page -

80 Policy Point Access Connections and Design Figure -. Conceptual Layout of I-/Trosper Road and Capitol Boulevard Improvements in the Build Alternative I-/Trosper Road Interchange Justification Report Policy Point Page -

81 Policy Point Access Connections and Design The existing and proposed spacing of interchanges and interchange configurations for the No Build Alternative and the proposed Build Alternative are the same as the Build Alternative would not alter existing interchange ramp access locations or configurations. Will the Modified and New Interchanges be Designed to Preclude Variances from Standards? No deviations from WSDOT design standards or design justifications are anticipated. The modified eastbound-to-northbound loop ramp at the northbound interchange will be designed for mph speeds. Sufficient acceleration distance would be provided for on-ramp traffic to reach the 0 mph mainline design speed prior to merging onto the mainline. What are the Conceptual Signing Plans for the New or Modified Interchanges? The conceptual layout and signing plans for the project area are illustrated in Figure -. These conceptual drawings show the proposed lane arrangement and signing plans to direct drivers through the revised interchange. This signing plan focuses on key directional signage to explain how the overall improvement project would reroute and/or manage traffic movement. It is anticipated that these plans may be revised during the design phase of the project to include other incidental signage. I-/Trosper Road Interchange Justification Report Policy Point Page -

82 Figure -: Conceptual Signing and Striping Plan for I-/Trosper Road and Capitol Boulevard Improvements Policy Point Access Connections and Design I-/Trosper Road Interchange Justification Report Policy Point Page -

83 Policy Point Land Use and Transportation Plans. POLICY POINT # LAND USE AND TRANSPORTATION PLANS 0 Introduction Policy Point addresses the question of whether the proposed access point revisions are compatible with the relevant land use and transportation plans for the area. This includes both local and regional land use plans, as well as local, regional and statewide transportation plans and planning requirements. It should be noted that currently only planning and engineering design services are funded for this project. Are the Proposed Access Point Revisions Compatible with Land Use Plans for the Area? 0 0 consistent with Comprehensive Plan land uses. This data, along with data from other community plans in Thurston County, was used by the Thurston Regional Planning Council (TRPC) in developing the regional travel demand model employed to prepare travel forecasts for the IJR. Thurston County and the city of Tumwater have prepared land use plans that comply with the Washington State Growth Management Act (GMA)(Revised Code of Washington (RCW), Chapter.0A). These plans include: City of Tumwater, Comprehensive Plan, Updated The proposed access revision on I- at the interchange with Trosper Road (Exit 0) is compatible with local and countywide land use plans. Compatibility is measured in two ways: Local land use plans provide the necessary guidance for continued urban development and redevelopment in Thurston County and the city of Tumwater. These plans identify policies and strategies to enhance economic vitality and quality of life, as well as providing opportunities to improve multimodal circulation. The access revision supports these objectives. Land use plans provide the basis from which travel forecasts were developed and used in evaluating the need for access revisions and in identifying the preferred alternative. Travel forecasts are based on household and employment projections that are 0 0 Thurston County, Countywide Planning Policies, 0 The Tumwater Comprehensive Plan includes policy and planning guidance that is relevant to the proposed project both in terms of land use designations, and requirements for consistency between land use and transportation plans. The Comprehensive Plan encourages residential, mixed use and neighborhood land use designations that support multimodal transit-oriented development. The Comprehensive Plan also makes specific recommendations with respect to encouraging economic development. It also establishes a Capitol Boulevard Community designation intended to foster development to create vibrant, multimodal places that encourage a variety of businesses particularly those that appeal to pedestrians. Thurston County s Countywide Planning Policies provide guidance to local communities in I-/Trosper Road Interchange Justification Report Policy Point Page -

84 Policy Point Land Use and Transportation Plans establishing comprehensive land use and transportation plans that meet countywide objectives. These policies support economic development, encourage multimodal transportation, encourage community placemaking, and require consistency between land use and transportation plans. Other relevant plans prepared and adopted by the city of Tumwater to provide further guidance to developing the proposed access revision include: City of Tumwater, Economic Development Plan, 00 (incorporated into the Comprehensive Land Use Plan) City of Tumwater, Capitol Boulevard Corridor Plan, 0 The Economic Development Plan provides guidance to implement the City s strategic vision for encouraging business investment and economic diversity by building on community strengths and establishing dynamic places. The Plan discusses creation of a vibrant and walkable business district in the Capitol Boulevard corridor using a targeted infrastructure investment strategy. Improved multimodal circulation such as that included in the proposed access revision is a key element of that strategy. The Capitol Boulevard Corridor Plan (CBCP) guides land use and infrastructure improvements to enhance the economic vitality and private development/redevelopment activity along one of the region s priority urban corridors. The Plan seeks to transform Capitol Boulevard from a primarily auto-oriented commercial strip to a multimodal mixed use corridor that integrates transportation and urban design solutions. In addition to its transit, bicycle and pedestrian recommendations, the Plan highlights the importance of reducing congestion in the vicinity of Trosper Road by making improvements to the Capitol Boulevard/Trosper Road intersection and adding local east/west street circulation in the vicinity of this intersection. The CBCP was the genesis of this IJR. Are the Proposed Access Revisions Consistent with State, Regional and Local Transportation Plans? The proposed improvements to the I- interchange at Trosper Road are consistent with state, regional and local transportation plans. These plans include: Washington State Transportation Plan, 0 (WTP)- Establishes a 0-year vision for the state s transportation system and recommends statewide transportation policies and strategies to the legislature and Governor. This Plan provides broad, policy-level support for improvements that enhance transportation mobility and safety, supports economic development, encourages stewardship and protects the environment. The proposed improvements support several strategies and actions in the 0 WTP including: o Making corridor improvements holistically including local multimodal street connections that support bicyclists, pedestrians and transit. o Strengthening the integration of land use and transportation systems including supporting infill I-/Trosper Road Interchange Justification Report Policy Point Page -

85 Policy Point Land Use and Transportation Plans and redevelopment in transit corridors o Supporting transit-oriented development. Washington State Highway System Plan (HSP), WSDOT, 00-0 Addresses current and future forecasted state highway needs based on investment options identified in the Washington Transportation Plan. The HSP identifies I- through the project area as a bottleneck (Trosper Road to the Pierce County line) with ramp metering as an initial suggested improvement to be followed by an in-depth urban feasibility study to identify longer-term solutions. More discussion is included under Policy Point #. 00 Regional Transportation Plan (RTP), TRPC establishes policies for multimodal transportation system development and land use/transportation planning compatibility. The RTP includes a regional project list that identifies future improvements to Capitol Boulevard between Trosper Road and Israel Road and includes modifications to the I- northbound off-ramp at Trosper Road. 0 0 o Providing for bicycle and pedestrian connectivity o Improving neighborhoods o Beautifying the corridor, and o Mitigating new development impacts Also identifies Capitol Boulevard as a regional strategy corridor where street widening is not the preferred option to address congestion problems. Capital Facilities Plan, 0-0, City of Tumwater Identifies a series of transportation system improvements affecting the project area including: I- /Trosper ramp revision, right-of-way and phase construction of proposed improvements to Capitol Boulevard, and development of a roundabout at the Capitol Boulevard/Trosper Road intersection. 0 Transportation Plan, City of Tumwater Incorporates the findings and recommendations of the CBCP with the objectives of: o Reducing congestion growth HSP Mobility chapter, pp.. I-/Trosper Road Interchange Justification Report Policy Point Page -

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87 Policy Point Future Interchanges 0 0. POLICY POINT # FUTURE INTERCHANGES Introduction Policy Point addresses whether the proposed access point revisions at the I-/Trosper Road interchange are compatible with a comprehensive network plan and with other known new access points and/or revisions to existing access points in the project vicinity. Are the Proposed Access Point Revisions Compatible with Other Future Interchange Improvements? Review of the current WSDOT State Highway System Plan (00-0), indicates that there are no new interchanges proposed on I- within three to five miles of the project area. However, the system plan identifies a number of freeway and /or interchange modifications that were reviewed for consistency with the proposed improvements. At several locations the need for additional study of existing or future bottlenecks or chokepoints has also been identified and discussed. The Highway System Plan (HSP) organizes projects into three tiers and also identifies Projects Tier I Solutions I-/ rd Avenue SW I-/Trosper Road to Pierce County line 0 0 projects that require further analysis. These levels are as follows: Tier I: Low cost projects with a high return on investment and short delivery schedules. Tier II: Moderate to Higher cost projects with potential network benefits. Tier III: Higher cost projects with corridor-wide benefits. Solutions that Require Further Analysis: This section of the HSP lists other projects that require further analyses before a recomm endation can be made. Study area projects listed in the HSP are summarized in Table -. Table -: Study Area Projects from WSDOT s Highway System Plan Improvement Signalize and channelize southbound offramp to provide separate right and left turn lanes Install ramp metering on approximately on-ramps in the northbound and southbound directions Project Completed Yes No Consistent with IJR Yes, no significant increase or drop in volumes with project May modify on-ramp traffic queues in project vicinity I-/Trosper Road Interchange Justification Report Policy Point Page -

88 Policy Point Future Interchanges Table -: Study Area Projects from WSDOT s Highway System Plan Continued Projects Improvement Project Completed Consistent with IJR Tier II Solutions I-/Tumwater Blvd Signalize northbound off-ramp and add eastbound acceleration lane on Tumwater Boulevard No Yes, no significant increase or drop in volumes with project I-/Tumwater Blvd Signalize southbound off-ramp and add right turn and acceleration lanes on Tumwater Boulevard Yes Yes, no significant increase or drop in volumes with project I-/ nd Avenue Install stop signs on local arterials (Desoto and nd Avenue) to create -way stop. No Yes, no significant increase or drop in volumes with project Tier III Solutions I-/Tumwater Blvd to I- /Trosper Road Consider adding HOV lanes that revert to general purpose use in the off-peak. Other solutions could include auxiliary lanes between interchanges or local frontage road improvements. No May impact traffic movement in study area depending on solution selected. Solutions that Require Further Analysis I-/Lewis County line to Tumwater corporate limits Rural Feasibility Study to evaluate feasibility of HOV lanes within Thurston County. Also consider dedicated freight lanes, high speed ground transportation, commuter rail, TDM and ITS strategies No Yes, no significant increase or drop in volumes with project is anticipated I-/Tumwater corporate limits to SR 0 vicinity Urban Feasibility Study to evaluate the feasibility of HOV lanes and a collector/distributor road system No Yes, no significant increase or drop in volumes with project is anticipated I-/Tumwater Blvd Install new 00-stall park and ride lot near Labor and Industries building on the east side of I- and north of Tumwater Boulevard No Yes, no significant increase or drop in volumes with project is anticipated I-/Tumwater Blvd Install partial cloverleaf or other interchange modifications to build on the Tier II solutions that addressed shorterterm problems. May also include ITS solutions. No Yes, no significant increase or drop in volumes with project is anticipated I-/Trosper Road to Pierce County line ITS improvements other than ramp metering No Yes, no significant increase or drop in volumes with project is anticipated I-/Trosper Road Interchange Justification Report Policy Point Page -

89 Policy Point Future Interchanges In addition to the Highway System Plan, the 00 Thurston Regional Transportation Plan was also reviewed to identify and assess compatibility with any potential interchange improvements in the project vicinity. These improvements are discussed in Table -. Table -: Projects from the Thurston Regional Transportation Plan ID Projects Improvement Consistent with IJR O I- Corridor Mobility Strategy Develop mobility strategy, consider HOV lanes, dedicated freight lanes, high capacity transit or other strategy Yes, strategy will need to consider I-/Trosper Road interchange area O Regional Park and Ride Investments Countywide implementation by WSDOT Yes 0 Based on the planned projects described in Table - and Table -, the proposed improvements to the I-/Trosper Road interchange discussed in this IJR are consistent with other existing interchanges and with other proposed freeway improvements in the project vicinity. I-/Trosper Road Interchange Justification Report Policy Point Page -

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91 Policy Point Coordination. POLICY POINT # - COORDINATION Introduction Policy Point addresses whether all projects and actions needed to successfully implement the proposed access point revisions have been programmed and funded. The policy point also requires documentation of all agencies, groups or other bodies that have been contacted regarding potential projects, and any past or planned public outreach. How have the Proposed Improvements been Coordinated with Other Improvement Projects in the Area? The preparation of this IJR has been closely coordinated with a stakeholder committee (IJR Support Team) comprised of all affected local, regional, state and federal agencies. Membership included: City of Tumwater Thurston County Intercity Transit Thurston Regional Planning Council (TRPC) Washington State Department of Transportation (WSDOT) Federal Highway Administration This committee has reviewed the development and evaluation of improvement options and alternatives for addressing congestion issues in the vicinity of the I-/Trosper Road interchange. Improvement options include identification of local projects that support and/or are coordinated with the proposed I- access revisions. In cooperation with WSDOT and TRPC, the City of Tumwater prepared the Capitol Boulevard Corridor Plan (CBCP) which identified a land use, economic, transportation and infrastructure strategy for development and redevelopment of the corridor south of Trosper Road. Consultation was also undertaken with the Washington State Patrol. Are There Other WSDOT Improvements that Need to Be Coordinated? As noted in Policy Point, there are several other improvements proposed by WSDOT in the vicinity of the recommended access revisions at the I-/Trosper Road interchange. Several of these improvements are anticipated at or near adjacent interchanges including I-/Tumwater Boulevard and I-/ nd Avenue. Additionally, several future studies have been suggested that would involve: Widening I- through the study area to add HOV/general purpose lanes and/or a collector/distributor road system ITS improvements along I- through the study area The TRPC Regional Transportation Plan also lists countywide implementation of park-and-ride facilities. Any of these projects that directly affect the I-/Trosper Road interchange will need to be coordinated with the proposed access revisions. Are There Other Local Improvements that Need to Be Coordinated? In addition to the recommended I- /Trosper Road access revisions at the northbound offramp, the project also includes several local I-/Trosper Road Interchange Justification Report Policy Point Page -

92 Policy Point Coordination street improvements in the vicinity of Trosper Road. These local improvements would be built following a phased implementation strategy to ensure that the overall interchange area operates acceptably and meets both short- and long-term objectives. As noted under Policy Point, the CBCP includes several additional projects in the study area that complement and support the proposed access revisions. These include: Extension of th Avenue from Lee Street to T Street. Extension of the north/south street east of Capitol Boulevard between Trosper Road and Linda Street to Lee Street. Intersection improvements including roundabouts at the intersections of Capitol Boulevard with T Street, X Street and Dennis Street. These improvements will be built as funding and land development/redevelopment activity warrants. How were Local and State Agencies Involved? Local and state agencies were involved throughout the planning process leading to this IJR, and continue to be involved as the IJR has been reviewed and approved. Key milestones in the coordinated and consultative process include: May 0 Kick-off meeting to brainstorm improvements to address existing and future congestion problems. June 0 Support Team meeting to screen improvement options, identify evaluation criteria, and develop initial alternatives. August 0 Support Team meetings to score alternatives. September 0 WSDOT meeting to discuss build-out options for the Capitol Boulevard/Trosper Road intersection, and the I- northbound off-ramp. October 0 Support Team meeting to discuss screening of alternatives. November 0 WSDOT meeting to provide briefing on development and screening of alternatives. January 0 Support Team reviewed the shortlist of alternatives after Step screening. Revisions to evaluation criteria were also discussed. February 0 Further discussion of shortlisted alternatives and evaluation process with Support Team. March 0 Support Team updated scoring criteria and weighting. April 0 Support Team reviewed results of the scoping and weighting process. May 0 Final results of Step alternatives evaluation and scoring were reviewed with the Support Team. September 0 - Completed Step Analysis using the same scoring criteria from Step. Step looked at operations of AM and PM. October 0 Review initial design concepts. I-/Trosper Road Interchange Justification Report Policy Point Page -

93 Policy Point Coordination February to June 0 Progress meetings with technical staff to review design alternatives. September 0 IJR kick-off meeting with Support Team. October 0 to early 0 IJR progress meetings with Support Team. How was the Public Involved? Providing meaningful venues for public participation was an important element of the CBCP and this IJR because the objectives of the project are to improve overall corridor mobility and accessibility, support economic development activity, and generally improve quality of life. An extensive public engagement effort was undertaken as part of the CBCP which provided the basis for the recommended access revisions and other corridor enhancements. Key elements of the CBCP community engagement effort included: Focus Group - Five meetings were held over the course of the study with a project focus group consisting of community representatives. public meetings were held including a broad spectrum of work sessions, special topic meetings, four public open houses, and a business/property owner open house. A residential survey was conducted of approximately,000 households in the Capitol Boulevard vicinity. Over 0 interviews were conducted with business and property owners Listen-in meetings were held with property owners, developers and the business community to address concerns. Outreach efforts included mailing over,00 letters/flyers, nearly,00 notifications (monthly to the project list throughout the duration of the project), three newspaper articles, and on-going communications via a project website hosted by TRPC. City Council held work sessions/reviews during July and November 0. See Figure - for an illustration of the type of public information material that was prepared during development of the CBCP. The CBCP was adopted in August of 0. Shortly after adoption, the City initiated an alternatives analysis and preliminary design study to refine and identify specific transportation system modifications consistent with the Plan. The CBCP did not include the two roundabout solution proposed in this IJR. Thus, to address issues associated with these and other improvements not specifically identified in the CBCP, additional public outreach was undertaken as part of this IJR effort. These activities included: January 0 City Council briefing on initial design concepts June 0 business owner meeting to review results of Step alternatives analysis. Discussion focused on the Ruby Ramp alternative and potential property impacts west of Capitol Boulevard and north of Lee Street. I-/Trosper Road Interchange Justification Report Policy Point Page -

94 Policy Point Coordination October 0 review results of Step ramp termini and the Trosper analysis of design concepts including Road/Capitol Boulevard roundabout. both the I-/Northbound Trosper Road Figure -: Public Information Materials I-/Trosper Road Interchange Justification Report Policy Point Page -