4.0 Conceptual Alternatives Innerbelt Curve. August 11, 2006 Page Innerbelt Curve: Background. Figure 4-1: Innerbelt Curve Section Location

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1 4.0 Conceptual Alternatives Innerbelt Curve Figure 4-1: Innerbelt Curve Section Location Chapter 4 details the Innerbelt Curve section of the Project. The chapter consists of four sections: 4.1 Background This discussion reviews the section s location within the corridor, its surrounding land uses, and its access locations. In addition, the needs for action identified during the Study are outlined. 4.2 Development of Conceptual Alternatives This discussion details the development process from the Study s Design Concept and Scope to the selection of two Innerbelt Curve conceptual alternatives: Innerbelt Curve Alternative E and Innerbelt Curve Alternative F. 4.3 Conceptual Alternatives This discussion describes the proposed improvements that comprise Innerbelt Curve Alternatives E & F, in addition to the No-Build Alternative. 4.4 Conceptual Alternatives Analysis and Conclusions This discussion summarizes the detailed conceptual alternatives analysis and selects Innerbelt Curve Alternative F to be carried forward into the Feasible Alternative analysis phase of the Project Step Innerbelt Curve: Background Location The Innerbelt Curve section (Figure 4-1) is the Project s northern terminus and is north of the Innerbelt Trench section (Chapter 5). The Innerbelt Curve is in an urban neighborhood of mixed land uses east of the City of Cleveland Central Business District (CBD). The area around the Innerbelt Curve has been identified as being mixed commercial and residential, including low income and minority population. Redevelopment efforts in this area are led by the St. Clair-Superior Development Corporation (to the east) and the Quadrangle Development Corporation. North of the Innerbelt Curve is the Cleveland lakefront and the city s Burke Lakefront Airport. To the east is an industrial and commercial area just south of I-90 that contains some larger manufacturers and wholesale/distributors, in addition to numerous small businesses. There are a number of small residential clusters throughout this area. West of the Innerbelt Curve and south of SR 2 (Memorial Shoreway) are vacant rail yards and outdoor storage. South of this area, adjacent to St. Clair Avenue, is a predominantly commercial neighborhood of small businesses, with clusters of residential properties. South of the Innerbelt Curve, in the Trench section of the Project, is a commercial and residential neighborhood. The Innerbelt Curve section consists of a fully directional system interchange between I-90 and SR 2. South of the I-90 / SR 2 interchange is the I-90 / Lakeside Avenue interchange, where access is available from eastbound I-90 and to westbound I-90. The next interchange to the south is at St. Clair Avenue. This partial interchange provides access from westbound St. Clair Avenue and southbound East 33 rd Street to eastbound I-90. Then, south of the I-90 / St. Clair Avenue interchange is the I-90 / Superior Avenue interchange. This interchange provides full access to Superior Avenue (via East 26 th Street for westbound I-90) and to the CBD from both eastbound and westbound I-90. August 11, 2006 Page 4-1

2 Needs Four needs were identified for the Innerbelt Freeway in the draft Purpose and Need statement completed in April 2003: (1) improve physical condition of existing bridge decks and roadway pavements; (2) improve operational performance; (3) improve safety; and (4) balance access. There is a need to improve the physical condition of existing bridge decks and roadway pavements of the Innerbelt Curve section prior to the end of the anticipated renewal period (2017). This need is founded upon two factors. First, the Lakefront Interchange Bridge (SR 2 over I-90) was constructed in Based on the performance of other Interstate bridges of similar age and construction, the bridge deck needs to be replaced. Second, the roadway pavements had a Pavement Condition Rating (PCR) of in A PCR of 100 represents a perfect / new roadway pavement with no observable distress, while a PCR of 0 represents roadway pavement with all distress types present at high levels of severity and extent. Based on the prediction that the PCR will fall below 75 in , there is a need for rehabilitation per ODOT s Pavement Design and Selection Process. There is a need to improve operational performance to achieve a minimum Level of Service (LOS) of D. The ODOT standard for Interstate freeway LOS is C. However, the Northeast Ohio Areawide Coordinating Agency (NOACA) established the goal that LOS D is the highest level of service practical for urban freeways in this region. Thus for all sections of the Innerbelt Freeway, LOS D or better is considered acceptable and LOS E and F are considered unacceptable. During the existing and future (2000 and 2025) AM peak hour, congestion occurs on westbound I-90 east of the SR 2 interchange. Congestion in this area begins at the Innerbelt Curve due to the 35 mph design speed at the curve and its restricted two-lane capacity through the curve. The operational performance problems appearing on westbound I-90 during the PM peak hour are attributable to issues located downstream of the Innerbelt Curve. There is a need to improve safety. The Study established that there is a direct link between the system configuration, operational performance, and safety. Based on a crash analysis covering 1997 through 1999, safety problems associated with the design (design deficiencies) and operational performance of the freeway have been identified. The crash rate for both eastbound (2.44/MVM) and westbound (2.37/MVM) I-90 through this section was twice the regional freeway average of 1.2/MVM. The eastbound and westbound crash rates are 2.8 and 2.7 times higher, respectively, than the statewide urban Interstate average of 0.877/MVM. The most often occurring crash type for the eastbound (46.5 percent) and westbound (37.4 percent) directions is rear-end crashes. In the eastbound direction, these elevated rates were attributed primarily to a combination of the driver s inability to safely enter and exit the Innerbelt Freeway from the numerous closely spaced ramps and the inability of drivers to safely adjust their travel speed in response to the slowing of traffic in advance of the Innerbelt Curve. In the westbound direction, the elevated rates were attributed primarily to drivers inability to safely adjust their travel speed in response to the daily recurring congestion that results from the numerous closely spaced ramps. Since operational performance and safety are directly linked to the roadway configuration, improving them includes correcting the existing freeway configuration to modern standards. During the Planning Phase of the Project, the Study determined that three types of design deficiencies in particular contribute to safety and operational performance problems along the Innerbelt Freeway: (1) improper reductions in the basic number of lanes (freeway); (2) inadequate acceleration, deceleration, weave or terminal spacing lengths (freeway ramps); and (3) inadequate curve radius (freeway mainline). From this list, instances of each these deficiency types can be found in the Innerbelt Curve section. The improper reduction in the basic number of lanes occurs along westbound I-90, where the four lanes east of the Innerbelt Curve are reduced to two lanes through the Innerbelt Curve. A representative example of an inadequate acceleration length is located at the Lakeside Avenue entrance ramp, where a stop sign exists at the entrance ramp terminal to the mainline. Finally, the I-90 curve through the SR 2 interchange (Innerbelt Curve) is adequate for a 35 mph design speed, while the posted speed is 50 mph. Finally, there is a need to balance access with operational performance and safety. Per ODOT standards, average urban interchange spacing should not be less than two miles with a minimum distance between each interchange of not less than one mile. The approximate distances between the interchanges at Superior Avenue, St. Clair Avenue, Lakeside Avenue, and SR 2 are 900 feet, 900 feet, and 1,100 feet. The current average service interchange spacing limits the potential to improve operational performance and safety. The interchange spacing actually decreases the level of access by degrading the operational performance and safety of the Innerbelt Freeway. The Lakeside Industrial area is an industrial area bounded approximately by Superior Avenue on the south, I-90 on the north, East 18 th Street on the west and East 82 nd Street on the east. Access to the area is provided by the full Superior Avenue interchange and the partial movements at the Lakeside and St. Clair Avenue interchanges. The geometrics of the Lakeside and St. Clair interchanges are so deficient that they do no appropriately serve the commercial truck traffic in the area. Thus, there is a need to balance the number of access points with the demand for access while providing for mainline freeway and local street system safety and operational efficiency. Furthermore, there is a need to improve upon the demand for access to and from the Lakeside Industrial area. 4.2 Innerbelt Curve: Development of Conceptual Alternatives This section explains the development and evolution of the conceptual alternatives evaluated in Step 5 for the Innerbelt Curve. The Design Workshops (see Section 3.4.2) conducted by the consultant/odot staff, enhanced by stakeholder input through public meetings or stakeholder group meetings (such as Community Development Corporations), represent key decision points in the development process. These discussions include key issues encountered during the development process and their resultant effects on each alternative. Figures 3-3a, 3-3b, and 3-3c provide a sequential outline of the evolution of the alternatives for each section of the Innerbelt, while Figures 4-2a and 4-2b present the decision flow diagram for the development of Innerbelt Curve conceptual alternatives. As shown, the development of Innerbelt Curve conceptual alternatives can be characterized by five basic concepts: minimal, single point urban interchange (SPUI) service interchange, partial cloverleaf service interchange, right-hand exit system interchange and left-hand exit system interchange. Figures illustrating the development of conceptual alternatives discussed in this section are located in Appendix A of this report. Figures 3-3a, 3-3b, 3-3c, 4-2a and 4-2b show the progression of the Innerbelt Curve alternatives through the development of conceptual alternatives through to the selection of the two conceptual alternatives to be analyzed. As can be seen from these figures, the initial iterations during the development of conceptual August 11, 2006 Page 4-2

3 Figure 4-2a: Development of Conceptual Alternatives Flow Diagram for Curve August 11, 2006 Page 4-3

4 Figure 4-2b: Development of Conceptual Alternatives Flow Diagram for Curve August 11, 2006 Page 4-4

5 alternatives primarily focused on geometric and operational concerns with some public involvement, as it was necessary to go through several iterations to find alternatives that had acceptable geometry and operation before requesting detailed public comment. Based on urban requirements, it was assumed that operation at level of service E or F would be unacceptable. As the process for development of conceptual alternatives continued, public involvement was intensified to help refine the alternatives, with a specific focus on accessibility to the Lakeside Industrial Area. To address this primary bottleneck, several key elements of the solution were identified to be incorporated into the alternatives to be developed for this section. First, the Innerbelt Curve was proposed to be flattened by increasing the curve radius to meet current design standards. As part of this proposed change, the lane imbalance on mainline I-90 would also be corrected by adding a third westbound lane through the curve into the Innerbelt Trench section. Because of these changes to the mainline alignment, the system interchange with SR 2 would also need to be reconstructed. It was not initially determined if this interchange replacement would be a system or service style interchange. To further improve traffic flow along I-90, conflict points (weaves) and poor ramp geometry would be mitigated if elimination is not possible. The Northeast Ohio Regional Sewer District (NEORSD) maintains a 141 inch (inside diameter) four ring shale brick sanitary interceptor that runs along the south side of Lakeside Avenue. Records indicate the NEORSD sanitary interceptor or combined sewer overflow (CSO) is approximately four feet below the profile grade of I-90 and runs through the Lakeside Avenue bridge abutment pile foundations. It carries the entire Cleveland downtown flow easterly to a treatment facility. Due to the topography of the CSO service area, the flat grade adds complexities to its possible replacement. Given this and the limited vertical information available at this step of the PDP, alternatives were developed to minimize or avoid potential impacts to the CSO. Minimal The process began with a minimal alternative (Minimal 1). The goal of this alternative was to develop a cost-effective solution that would maintain as many of the existing access points as possible, while still removing the operational problems associated with the lane-drops through the interchange. To accomplish this, the mainline I-90 curve was flattened to meet existing design standards and the westbound lane drop was eliminated. The system interchange was reconfigured to maintain all existing connections except the St. Clair Avenue on-ramp to eastbound I-90. There were many problems identified related to this alternative. First, there were large operational deficiencies caused by inadequate weave lengths and poor ramp geometry. Further, there were a number of geometric deficiencies identified, which included deficient curve radii, gore-to-gore spacing and interchange spacing. The poor operation and geometric deficiencies associated with this alternative caused it to be removed from further consideration during Workshop 1 and all further development work on the minimum alternative was suspended. Service Interchange At the time development of conceptual alternatives began, work was underway on the Cleveland Lakefront Plan. It ran parallel to the work being completed on the Project. The Cleveland Lakefront Plan focused on the reconstruction of SR 2 from Edgewater Park in the west, across the Cuyahoga River, past the downtown to its intersection with I-90 at the Innerbelt Curve and, then, east along the I-90/SR 2 alignment to Gordon Park. Several of the alternatives being considered by the parallel Cleveland Lakefront Study proposed downgrading SR 2 from Edgewater Park to I-90 from a freeway style facility to an urban boulevard (i.e. city street). This urban boulevard would then be perpetuated to the east along the existing alignment of the North Marginal Road. For planning purposes, this urban boulevard was referred to as the Lakefront Boulevard. One of the key aspects identified by the Cleveland Lakefront Study was that this Lakefront Boulevard be a continuous alignment. As part of the coordination work with the Cleveland Lakefront Study, options were developed which downgraded the I-90/SR 2 interchange from a system interchange to a service interchange. Specifically, three alternatives that utilized Single Point Urban Interchange (SPUI) style service interchanges and three alternatives that utilized Partial Cloverleaf style service interchanges were developed. All of these service interchange alternatives flattened the Innerbelt Curve along I-90, provided a third lane westbound through the curve and removed the St. Clair/Lakeside ramps. Single Point Urban Interchange (SPUI) Service Interchange The three SPUI alternatives that were developed were similar in concept, but were differentiated by how they connected traffic coming from/to the interchange of I-90/SR 2 with the proposed Lakefront Boulevard. The first alternative (SPUI 1) kept SR 2 continuous and tied it directly into South Marginal Road east of the interchange. The Lakefront Boulevard alignment was then discontinuous at an intersection west of the interchange. Thus, traffic wishing to access the interchange with I-90 would be serviced by the through movement of this intersection, while traffic wishing to stay on the Lakefront Boulevard would need to execute a turn. The second alternative (SPUI 2) kept the Lakefront Boulevard alignment continuous at the intersection west of the interchange. This forced traffic coming to or from the interchange with I-90 to make a turn movement at this intersection. The third alternative (SPUI 3) made both the access to the interchange and the Lakefront Boulevard continuous. The Lakefront Boulevard crossed back to the North Marginal Road alignment east of the interchange just to the east of East 40 th Street. In all of the SPUI alternatives considered, analysis of the signal within the SPUI showed that the operation of the interchange to be unacceptable. The high volume of traffic that needed to be serviced far exceeded the capacity of the service interchange. Further, the use of a service interchange, with the associated traffic signal, would only be possible if the Cleveland Lakefront Study selected an alternative that downgraded SR 2 to an urban boulevard. Because of the operational failure of these designs and to preserve independent utility of the alternatives developed by the Project for the Innerbelt Curve, the use of a service interchange was dropped from further consideration. This resulted in alternatives SPUI 1, SPUI 2 and SPUI 3 being removed from further development at Workshop 1 and all further work on the SPUI concept was suspended. Partial Cloverleaf (PAR-CLO) Service Interchange Development of the first two Partial Cloverleaf (PAR-CLO) alternatives was simultaneous to the development of the SPUI alternatives. The first PAR-CLO alternative (PAR-CLO 1) used many of the existing geometric ideas, and tied the interchange into a single intersection along the SR 2/North Marginal Road alignment. This approach allowed the proposed Lakefront Boulevard alignment to be continuous, while forcing traffic coming from/to the interchange with I-90 to execute a turn at the intersection west of the interchange. There were several geometric deficiencies associated with this alternative, which included inadequate weave length and vertical grade deficiencies. Operationally, this alternative had much the same problem exhibited by the SPUI alternatives. The heavy movements associated with the access to I-90 in the intersection just west of the interchange resulted in failing operation of that intersection. In an attempt to fix the operational and geometric deficiencies created by the first PAR-CLO alternative, the concept was modified into a split-trumpet (PAR-CLO 2). To better accommodate the heavy turning movements associated with access from/to the interchange, this alternative utilized two-intersections to split August 11, 2006 Page 4-5

6 the movements of the interchange and to allow for better ramp geometry. However, operational analysis determined that the split intersections also failed. Further, the weave created on the interstate in the westbound direction between the SR 2 interchange and the Superior Avenue interchange failed due to its inadequate length. At the urging of city staff from the City of Cleveland working on the Cleveland Lakefront Study, a third attempt was made to modify the PAR-CLO concept. PAR-CLO 3 was designed to fix the operational deficiencies of PAR-CLO 2. To further spread out the large amount of traffic utilizing the intersections between the access road to the interchange and the Lakefront Boulevard, a third intersection was created along the Lakefront Boulevard. Further, this would allow for the lengthening of the weave distance between the SR 2 and the Superior Avenue interchanges. However, this change, coupled with pulling the Superior Avenue exit ramp off of I-90 prior to the SR 2 interchange, created deficient ramp grades and ramp terminal designs in this alternative. Because of these geometric deficiencies, PAR-CLO 3 was removed from further consideration in Workshop 2 and all further work on the PAR-CLO concept was suspended. Based on the analysis of the service interchange alternatives SPUI 1, SPUI 2, SPUI 3, PAR-CLO 1, PAR- CLO 2 and PAR-CLO 3, it was determined that a service interchange style design would not provide sufficient capacity for the large traffic volumes projected for this interchange. System Interchange All of the system interchange solutions considered addressed the key solution components outlined above. First, mainline I-90 was flattened to bring the radius of the Innerbelt Curve to current design standards. Next, an additional lane was brought westbound around the curve into the trench area to eliminate the lane imbalance that, coupled with the severe geometry of the curve, caused one of the primary bottlenecks in the study area. Finally, the ramps servicing St. Clair Avenue (on-ramp to eastbound I-90) and Lakeside Avenue (off-ramp from eastbound I-90 and on-ramp to westbound I-90) were eliminated due to their poor geometry, poor operation, contribution to safety problems and to improve the weave between the SR 2 and Superior Avenue interchanges. Right-Hand Exit System Interchange The first of the true system interchange alternatives developed was the Right-Hand Exit System Interchange (RHE 1). In this alternative, the eastbound SR 2 to westbound I-90 ramp was designed as a traditional righthand exit west of the interchange with I-90. In this concept (RHE 1), SR 2 followed the existing alignment into the interchange area and South Marginal Road was severed prior to crossing I-90. This alternative had several geometric and operational deficiencies associated with it and was dropped. However, this alternative served as the base scheme for the development of RHE 2, RHE 3 and RHE 4, which all made changes to this alternative to better address geometric, operational and access needs in the Innerbelt Curve area. During meetings held with the St. Clair/Superior CDC ( ) and the Scoping Committee (1-8-04, and ) members of the community expressed concern that South Marginal Road no longer provided access across I-90 as shown in the RHE 1 alternative. In RHE 2, the concept developed as part of RHE 1 was modified slightly to provide a connection of South Marginal Road across I-90. This was done to see what impacts this would have on the overall layout of the interchange. The operational and geometric deficiencies associated with RHE 1 still exist in this alternative. However, this analysis showed that the perpetuation of the South Marginal Road connection would be possible and this idea would be incorporated in later variations of the system interchange alternatives. This alternative was carried forward into Workshop 3 to be used as a basis to develop additional alternatives to address the remaining operational and geometric deficiencies. A further concern expressed by stakeholders at the four meetings was in regard to access from eastbound SR 2 to Superior Avenue. Under the RHE 1 concept, the westbound I-90 ramp to Superior Avenue exits the mainline freeway before traffic from the eastbound SR 2 to westbound I-90 enters. Under this configuration, it would not be possible to access Superior Avenue from eastbound SR 2. To address this access concern, the next alternative (RHE 3) built off of RHE 1 by adding a ramp connection between the eastbound SR 2 to westbound I-90 ramp and the westbound I-90 to Superior Avenue ramp. This connector ramp allows traffic from eastbound SR 2 to access either Superior Avenue or westbound I-90. Due to poor geometry, difficulty in providing adequate signage for the movements provided and poor operation, RHE 3 was dropped from further consideration at Workshop 2. However, the need to provide adequate access from eastbound SR 2 to Superior Avenue was preserved as a critical comment and was incorporated into the alternative Innerbelt Curve E which is the alternative that was selected as the conceptual alternative from those that were developed based on the right-hand exit scheme. City of Cleveland staff working on the Cleveland Lakefront Study requested that the right-hand exit system interchange scheme attempt to integrate a continuation of the Lakefront roadway via the North Marginal Road alignment. As such, the RHE 4 alternative attempted to integrate continuity of the North Marginal Road alignment as a two-way roadway east of the interchange area with the existing SR 2 alignment in the interchange area. After exiting from SR 2 the eastbound ramp was split to provide access to both North Marginal Road and westbound I-90. In addition, the South Marginal Road alignment was preserved across the I-90 alignment. RHE 4 was also carried forward into Workshop 3. In Workshop 3 the team again examined Alternatives RHE 2 and 4. Both were determined to have too tight of geometry and low design speeds to be effective and revisions were made to address these issues evolving into two new alternatives, RHE 5 and RHE 6. RHE 5 continued to build upon the concept put forth in RHE 4, which emphasized developing a continuous North Marginal Road alignment with SR 2 and perpetuating South Marginal Road across the I-90 alignment. In this iteration, the movement to North Marginal Road was separated from the movement to westbound I-90 by utilizing two separate ramps instead of a combined ramp. Because of the required distance between these successive off-ramps, this alternative stretched the I-90/SR 2 interchange out quite a bit to the west. As such, the new footprint of the alternative overlapped many of the alternatives being considered as part of the Cleveland Lakefront Study. This alternative was determined to be inconsistent with project needs for both the Innerbelt and Lakefront projects, as such this alternative was removed from further consideration in Workshop 4. RHE 6 modified RHE 2 to eliminate the East 18 th Street interchange west of I-90 and replaced it with an intersection with North Marginal Road. The removal of the interchange also removed the short weaves that were created between the East 18 th Street interchange and the I-90 interchange. Again, this alternative was determined to be inconsistent with project needs for both the Innerbelt and Lakefront projects, which kept this alternative from being pursued further after Workshop 4. August 11, 2006 Page 4-6

7 After Workshop 4, the RHE concept was further modified to create what would become Conceptual Alternative Curve E. This Curve E alternative addressed public concerns regarding access by perpetuation of the South Marginal Road across the I-90 alignment. Further, to provide access to Superior Avenue from eastbound SR 2 the configuration of several ramps was modified. First, what had been shown as a combined exit from westbound I-90 to both SR 2 and Superior Avenue was separated into two exit ramps. The exit to Superior Avenue was relocated downstream of the entrance ramp from eastbound SR 2, allowing that movement to be made via an auxiliary lane. This relocation reinstates the mainline weave at this location, but sufficient distance was provided to allow for adequate operation of that weave. Finally, North Marginal Road was realigned to bulb out around the alignment of the westbound I-90 to westbound SR 2 ramp, which eliminated a costly bridge structure. This alternative was re-examined at each successive workshop (5, 6 and 7), was presented to and commented on by stakeholders at two Advisory Committee meetings ( and ) and several small group stakeholder meetings (e.g. St. Clair/Superior CDC meeting on ) and was eventually selected as the most viable alternative based on the right-hand exit scheme. Thus, it was selected as a conceptual alternative. Left-Hand Exit System Interchange The other system interchange design analyzed was the Left-Hand Exit System Interchange. Two alternatives were developed in concept in Workshop 3 and refined prior to Workshop 4. In these alternatives, the tight eastbound SR 2 to westbound I-90 ramp in the RHE system interchange concept was re-designed to come off of the alignment as a left-hand exit. This change in ramp configuration would increase the design speed of the ramp. The first alternative (LHE 1) was developed utilizing the RHE 5 alternative as a base. However, this early iteration utilized a broken-back curve (a curve followed by a short tangent followed by a curve) on the proposed alignment of the left-hand exit ramp from eastbound SR 2 to westbound I-90. As such, this alternative was modified to correct this deficiency, becoming LHE 2. As part of this modification, the ramp was re-designed as a compound curve that spanned I-90, the westbound I-90 to westbound SR 2/Superior Avenue ramp, and North Marginal Road. Concerns regarding the complexity and geometric design of that structure caused the alternative to be further modified to reduce the complexity of this structure. These refinements were made prior to Workshop 5 and became LHE 3 and LHE 4. LHE 3 realigned the westbound I-90 to westbound SR 2/Superior Avenue ramp exit gore to the north. It also pushed the alignment of North Marginal Road into the Burke Lakefront Airport property. These two changes made the eastbound SR 2 to westbound I-90 ramp structure much less complex, addressing that concern. However, as with the initial RHE alternatives, access from eastbound SR 2 to Superior Avenue was not provided. To accommodate this concern raised by the stakeholders, the design was further modified to create LHE 4 which used a slip-ramp from the eastbound SR 2 to westbound I-90 ramp to connect to the Superior Avenue exit ramp. Borrowing from the strategy used in development of Curve E which separated the westbound I-90 to SR 2 and Superior Avenue into individual ramps, in Workshop 6 Curve F was created. This creation of individual ramps, while reintroducing a weave onto westbound mainline I-90 between the eastbound SR 2 on-ramp and the Superior off-ramp, solved the access problem to Superior Avenue. Furthermore, the utilization of the LHE concept allowed this weave to be lengthened over what could be provided by the RHE concepts. This alternative was re-examined in Workshop 7, was presented to and commented on by stakeholders at an Advisory Committee meeting (6-9-05) and several small group stakeholder meetings (e.g. St. Clair/Superior CDC meeting on ) and was eventually selected as the most viable alternative based on the left-hand exit scheme. This final public involvement also resulted in a minor reconfiguration of this alternative to reestablish the interchange west of I-90 along SR 2 that provides access to South Marginal Road and the Municipal Parking lots. After this final revision, it was selected as a conceptual alternative. 4.3 Innerbelt Curve: Conceptual Alternatives In addition to the No-Build Alternative, two conceptual alternatives were selected for analysis: Innerbelt Curve Alternative E (Curve E) and Innerbelt Curve Alternative F (Curve F). The Innerbelt Curve conceptual alternatives physically can connect to any of the Innerbelt Trench conceptual alternatives. However, if an operationally failing alternative were selected (such as the No Build), there would be operational failures in the adjacent sections. These operational failures would result in queuing into adjacent sections that would eliminate benefits intended by proposed improvements within adjacent sections. No-Build Alternative The Innerbelt Curve No-Build Alternative (Figure 4-3) serves as the baseline alternative. Because much of the Innerbelt was built in the 1950s and 1960s, the bridges and roadway pavements are in need of reconstruction or rehabilitation. Under the No-Build alternative, I-90 will undergo pavement reconstruction. Ramp and connecting roadway pavements will also undergo reconstruction. The Lakefront Interchange Bridge (SR 2 over I-90) deck will be replaced within the renewal time frame. This work only addresses the physical condition of the facility and does not address operational performance, safety, and access. Capacity is not increased and changes will not be made to lane widths, shoulder widths, bridge widths, structural capacity, horizontal / vertical alignments, grades, stopping sight distance, pavement cross slopes, superelevation, or horizontal / vertical clearance, under the No-Build Alternative. See Figure 4-6a for the geometric layout of the No-Build Alternative. Innerbelt Curve Alternative E The Innerbelt Curve Alternative E (Figure 4-4) is the first of two build alternatives. To improve the physical condition of the facility, the existing bridges and roadway pavements will be replaced with completely new construction. To improve operational performance and safety, the radius of the existing 35 mph mainline horizontal curve (Innerbelt Curve) will be increased to provide for a 55 mph design. See Figure 4-7a for the geometric layout of Innerbelt Curve Alternative E. The improper reduction in the basic number of lanes along westbound I-90 through the SR 2 interchange will be eliminated. The mainline will consist of three through lanes in each direction, with additional auxiliary lanes between the SR 2 and Superior Avenue interchanges. Roadway configurations that fail to meet current design standards are also improved. This includes enhancing ramp terminal designs and spacing. Spacing is addressed along I-90 by consolidating local access at Lakeside and St. Clair Avenues to Superior Avenue. This includes removing the eastbound I-90 entrance ramp from St. Clair Avenue and the exit ramp to Lakeside Avenue. Along westbound I-90, the entrance ramp from Lakeside Avenue is removed. This consolidation is a balance of access, operational performance, and safety: access points are improved and / or removed until acceptable operational performance measures geometric configurations are met. As part of the reconstruction of the Norfolk August 11, 2006 Page 4-7

8 Southern railroad bridge over I-90, the underpass of East 38 th Street between Hamilton and Lakeside Avenues will be closed. The existing underpass is primarily used by traffic coming from the I-90 to Lakeside Avenue ramp and does not have sufficient vertical clearance to accommodate trucks. The key difference between the two build alternatives is the geometric design for the eastbound SR 2 to westbound I-90 ramp. The Innerbelt Curve Alternative E utilizes a right-hand exit prior to the interchange crossroad (I-90). Innerbelt Curve Alternative F utilizes a left-hand exit after the crossroad. There are three reasons for having two Conceptual Alternatives. First, a right-hand exit is preferred over a left-hand exit by standards based on the concept of driver expectancy. Second, the design speed of the ramp from the lefthand exit meets the design speed standards for a loop ramp, where the ramp from the right-hand exit does not meet the design speed standards of a directional ramp due to space limitations. Third, the ramp design from the left-hand exit provides the ability to maintain all connections at the existing SR 2 / South Marginal Road (municipal parking lot) interchange, west of the I-90 / SR 2 interchange. The ramp design from the right-hand exit precludes the ability to maintain the eastbound SR 2 entrance ramp. Innerbelt Curve Alternative F The Innerbelt Curve Alternative F (Figure 4-5) is the second of two build alternatives. The basic concept for the Innerbelt Curve Alternatives E and F is the same. The improvements proposed to address the facility s physical condition; operational performance, safety, and access are the same in both alternatives. See Figure 4-8a for the geometric layout of Innerbelt Curve Alternative F. As outlined in the description of Innerbelt Curve Alternative E, the key differences between these alternatives stems from the configuration of the eastbound SR 2 to westbound I-90 ramp. The configuration of this ramp affects ability to maintain complete access at the SR 2 / South Marginal Road interchange. This alternative utilizes the left-hand exit and maintains full access at the SR 2 / South Marginal Road interchange, whereas the right hand exit of Innerbelt Curve Alternative E precludes the ability to maintain the eastbound SR 2 entrance ramp. 4.4 Innerbelt Curve: Conceptual Alternatives Analysis and Conclusions The Conceptual Alternatives were evaluated and compared on how well they addressed the seven performance measures (Section ). The following text and Table 4-1 summarizes and compares the Conceptual Alternatives analysis of the Innerbelt Curve section. Physical Condition The No-Build Alternative and Innerbelt Curve Alternatives E and F address the need to improve the physical condition of the roadway pavements and bridge deck of the Innerbelt Curve section prior to the end of the anticipated renewal period. The alternatives differ in how it is addressed. The No-Build Alternative reconstructs the existing roadway pavements and replaces the bridge deck of the Lakefront Interchange Bridge. Innerbelt Curve Alternatives E and F are on new alignment; therefore, the roadway pavements, structures, and other roadside features are completely new construction. Safety The No-Build Alternative does not address the need to improve safety, whereas Innerbelt Curve Alternatives E and F do. Innerbelt Curve Alternatives E and F reduce the number of design deficiencies from 44 to two and one, respectively. Furthermore, the build alternatives reduce the number of weaving sections from five found in the No-Build Alternative to two. See Figures 4-6a through 4-8c for geometric deficiency and weaving section information of the No-Build Alternative and Innerbelt Curve Alternatives E and F. The difference between Innerbelt Curve Alternatives E and F is the geometry of the eastbound SR 2 ramp to westbound I-90. During the Design Workshops, safety concerns were expressed regarding driver expectations of this ramp s geometry for Innerbelt Curve Alternative E. To make this movement, the vehicle exits SR 2 via a high-speed terminal to the right (south) and then almost immediately turn left (north). Then, the vehicle must slow and navigate a low-speed (25 mph) curve, turning nearly 180 degrees. Then, the vehicle must accelerate to enter westbound I-90, which is a high-speed facility. This movement also includes traveling beneath mainline SR 2 and several ramps, which prevents the driver from being able to see the complete ramp. Innerbelt Curve Alternative F utilizes a left hand exit terminal, which leads to a looping fly-over ramp, for the eastbound SR 2 to westbound I-90 traffic movement. During the Design Workshops, concerns were expressed with this alternative regarding driver expectations of an exit terminal being located on the left side. The issue is that left-hand exits are considered contrary to driver expectations when most terminals are on the right side. In these situations, signing should receive special attention so that drivers are notified well in advance of the unusual exit location. In this particular situation, ample room is available for signing. The nearest major interchange west of the exit is just over a mile away. In addition to this, the innermost lane runs even further west without disturbance from entrance or exit terminals; therefore, the innermost lane can be signed as a drop lane as far back from the exit as necessary to prevent driver confusion. In addition, the geometric configuration of this ramp starts with a design speed of 30 mph. The design speed then increases throughout the length of the ramp until the high-speed entrance terminal with westbound I-90. The increasing design speeds of the Innerbelt Curve Alternative F ramp configuration were viewed as a better configuration than the high-low-high varying design speeds of this ramp configuration with Innerbelt Curve Alternative E. With the ability to provide sufficient signing for the left-hand exit terminal and the increasing design speed of the ramp, Innerbelt Curve Alternative E was viewed as being geometrically better and safer. Operational Performance The No-Build Alternative does not address the need to improve operational performance, whereas Innerbelt Curve Alternatives E and F do. The No-Build alternative continues to experience mainline failures during the AM peak hour. The geometric layouts of Innerbelt Curve Alternatives E and F are similar; thus, the operational performance of both alternatives is similar. All segments of both build alternatives operate at an acceptable LOS D or better. Even though VHD and average speeds slightly favor Innerbelt Curve Alternative F, they are relatively small and are negligible due to the size of the network. The build alternatives realize a decrease of AM VHD. The slight increase in PM peak hour VHD of the build alternatives over the No-Build Alternative is the result of a change of the network and not increased congestion. This is evidenced by the nearly identical average speeds. August 11, 2006 Page 4-8

9 Accessibility The No-Build Alternative does not change existing access. Innerbelt Curve Alternatives E and F have safety and operational performance improvements, which come at the cost of consolidating several closely spaced access points. This consolidation balanced the number of access points with the demand for access while providing for mainline freeway and local street system safety and operational efficiency. With the elimination of the St. Clair and Lakeside Avenues ramps in Innerbelt Curve Alternatives E and F, freeway operation and safety are improved. However, due to the consolidated of access at Superior Avenue, truck traffic wishing to access the Lakeside Industrial area must utilize the local street network. Because some of these streets are residential in nature, there has been public concern raised regarding the impact of additional truck traffic. Strategies for addressing this concern will be developed during Step 6. Accessibility differs between Innerbelt Curve Alternatives E and F. This difference is rooted in the same ramp that is the focus of the safety discussion. The location of the eastbound SR 2 to westbound I-90 exit ramp terminal for Innerbelt Curve Alternative F provides the ability to maintain all connections at the existing SR 2 / South Marginal Road interchange, west of the I-90 / SR 2 interchange. The location of this exit ramp terminal for Innerbelt Curve Alternative E precludes the ability to maintain the eastbound SR 2 entrance ramp from South Marginal Road. Innerbelt Curve Alternatives E and F remove the slip ramp connection between the eastbound SR 2 to eastbound I-90 ramp and South Marginal Road. This slip ramp does not comply with design standards. Connection to South Marginal Road is provided in Innerbelt Curve Alternatives E and F via the Municipal Parking Lot ramp west of I-90. Maintenance of Traffic / Constructability The No-Build alternative does not provide the minimum number of mainline through-lanes during construction in accordance with the Permitted Lane Closure Policy. Innerbelt Curve Alternatives E and F provide the ability to maintain the minimum number of mainline through-lanes. Neither Innerbelt Curve Alternatives E nor F has substantial constructability differences between them. The sequencing difference between the two regarding North Marginal Road does not establish a preference between the alternatives. Environment For the reason that the No-Build Alternative is a basic rehabilitation of the existing facility, no environmental impacts are expected. Considering Innerbelt Curve Alternatives E and F, the differences included acreage of net right-of-way returns and one neighborhood street impact. For both build alternatives, impacted neighborhood streets include Lakeside Avenue, St. Clair Avenue, East 26 th Street, and East 33 rd Street. These are the result of the Lakeside Avenue / East 26 th Street and St. Clair Avenue ramp removals, which shifts the local street traffic patterns. The difference between the build alternatives is that Innerbelt Curve Alternative E severs a connection between SR 2 and South Marginal Road and Innerbelt Curve Alternative F does not. Both of these favored Innerbelt Curve Alternative F with a difference of 2.5 net returned acres and one less neighborhood street impact. Cost The No-Build Alternative only addresses the need to improve physical condition with a cost of $45 million. Innerbelt Curve Alternatives E and F address all of the stated needs with costs of $160 million and $150 million, respectively. Comparison of Alternatives Innerbelt Curve Alternatives E and F address all of the needs: physical condition, operational performance, safety, and access. The No-Build Alternative only addresses physical condition and does not address problems with operational performance and safety. Since Innerbelt Curve Alternatives E and F address all of the needs, additional examination of how well each alternative addressed these needs is necessary to make a selection. The comparison revealed that both alternatives are identical in addressing physical condition and are nearly the same regarding operational performance and maintenance of traffic / constructability. They differ regarding safety, accessibility, and cost, all of which favor Innerbelt Curve Alternative F. These differences are based on the eastbound SR 2 ramp to westbound I-90. The configuration of this ramp with Innerbelt Curve Alternative F is better geometrically and allows maintenance of a complete interchange along SR 2 at South Marginal Road. Innerbelt Curve Alternative F is $10 million less than Innerbelt Curve Alternative F. Summary Innerbelt Curve Alternative F (Figure 4-5) is selected to be carried forward as a Feasible Alternative analysis phase of the Project Step 6. Innerbelt Curve Alternative E (Figure 4-4) is not being carried forward. Although Alternative E is feasible, it is not being carried forward to Step 6 since it offers no advantages in any category evaluated: Alternative F provides greater safety that Innerbelt Curve Alternative E due to better geometry of the eastbound SR 2 to westbound I-90 ramp. Alternative F provides greater accessibility than Alternative E because it maintains a full interchange at SR 2/South Marginal Road. Alternative F has less potential neighborhood street impacts than Alternative E. Alternative F has the same potential environmental impacts as Alternative E. Alternative F is estimated to cost $ 10 million less than Alternative E. Strategies for addressing truck access to the Lakeside Industrial area will be developed during Step 6. August 11, 2006 Page 4-9

10 Table 4-1: Alternatives Comparison PHYSICAL CONDITION Pavement No-Build Alternative E Alternative F Full-depth New Construction New Construction Replacement Bridges Deck Replacement New Structure New Structure SAFETY Design Deficiencies Number of Weaves OPERATIONAL PERFORMANCE LOS See Fig. 4-9 See Fig See Fig AM Vehicle Hours of Delay 195 (38 mph) 64 (48 mph) 59 (49 mph) PM Vehicle Hours of Delay 54 (48 mph) 68 (48 mph) 68 (49 mph) Deficient Weaves ACCESSIBILITY Full Interchanges Partial Interchanges I-90 / Superior I-90 / SR 2 SR 2/S. Marginal I-90/St. Clair I-90/Lakeside I-90 / Superior I-90 / SR 2 SR 2/S. Marginal I-90 / Superior I-90 / SR 2 SR 2/S. Marginal None SR 2/E 38th Maintenance of Traffic / Constructability (#Meets minimum number of mainline through-lanes per PLCP *Three lanes can be maintained once offline portion of I-90 is constructed) I-90 EB Superior Ave. to SR2 WB exit ramp 2 3# 3# I-90 EB SR2 WB exit ramp to SR2 EB 2 3# 3# I-90 EB SR2 EB entrance ramp to East 55th 2 4# 4# I-90 WB East 55th Street to SR2 WB exit 2 4# 4# I-90 WB SR2 WB exit ramp to SR2 EB 1 2#* 2#* I-90 WB SR2 EB entrance ramp to Superior 2 3# 3# ENVIRONMENT Residential Property Structure Takes Institutional Property Structure Commercial / Industrial Property Right-of-Way Takes (acres) Returns (acres) Net Takes (acres) 0 (-1.0) (-3.5) Historic Structure / District Impacts Park Land Impacts Potentially Contaminated Site Impacts 0 Phase II - 3 Phase II - 3 Neighborhood Street Impacts COST Cost in Millions (2005 dollars) $45 $160 $150 Highlighted columns are conceptual alternatives that are selected to be carried forward into the Feasible Alternative analysis phase of the Project Step 6. August 11, 2006 Page 4-10

11 Figure 4-3: No-Build Alternative August 11, 2006 Page 4-11

12 Figure 4-4: Innerbelt Curve Alternative E August 11, 2006 Page 4-12

13 Figure 4-5: Innerbelt Curve Alternative F August 11, 2006 Page 4-13

14 Figure 4-6a: No-Build Alternative Geometric Layout and Deficiencies August 11, 2006 Page 4-14

15 Figure 4-6b: No-Build Alternative Geometric Deficiencies Location Figure 4-6a Ref. No. Design Deficiency Project Design Criteria Deficiencies Standards** Design Speed Proposed Design Speed 0 Improper Reduction in Basic Number of Lanes Horizontal Alignment 5 30' 00" (R = 1,042') 55 mph 12 30' 00" (R = 458') 35 mph 2 Horizontal Alignment 5 30' 00" (R = 1,042') 55 mph 11 58' 39" (R = 478') 35 mph 3 Horizontal Alignment 5 30' 00" (R = 1,042') 55 mph 15 07' 03" (R = 379') 35 mph 4 Stopping Sight Distance 495' 55 mph 200'± 30 mph 5 Median Shoulder: 6-Lane Urban, Truck DDHV > '-0" - Varies 2'-0"± to 8'-0"± - 6 Outside Shoulder: 6-Lane Urban, Truck DDHV > '-0" - Varies 8'-0"± to 13'-0"± - 7 Vertical Alignment: Maximum Grade Break 0.4% 55 mph 0.43% 50 mph 8 Vertical Alignment: Maximum Grade Break 0.4% 55 mph 0.47% 45 mph 9 Vertical Alignment: Maximum Grade Break 0.4% 55 mph 0.44% 50 mph I Vertical Alignment: Maximum Grade Break 0.4% 55 mph 0.44% 50 mph 11 Vertical Alignment: Crest Vertical Curve 495' 55 mph mph 12 Vertical Alignment: Sag Vertical Curve 495' 55 mph mph 13 Vertical Clearance: EB Under St. Clair 15'-6" - 15'-3" - 14 Vertical Clearance: WB Under St. Clair 15'-6" - 15'-2" - 15 Vertical Clearance: EB Under NS Railroad 15'-6" - 14'-9" - 16 Vertical Clearance: WB Under NS Railroad 15'-6" - 14'-10" - 17 Vertical Clearance: EB Under Lakeside 15'-6" - 15'-4" - 18 Vertical Clearance: WB Under Lakeside 15'-6" - 15'-2" - Ramp: EB I-90 from St. Clair 19 Vertical Clearance: EB Under CSX 15'-6" - 15'-3" - 20 Vertical Clearance: WB Under CSX 15'-6" - 15'-0" - 21 Horizontal Alignment: Lower 21 00' 00" (R = 273') 30 mph* 38 36' 44" (R = 148') < 25 mph 22 Acceleration Length (from stop) 960' - 30' ± - 23 Taper Rate 50:1-7.5:1 ± - 24 Deceleration Length 800' - 0' ± - Ramp: EB I-90 to Lakeside Ramp Terminal Spacing: EN-EX: Service to Service: Full 25 Frwy: between St. Clair and Lakeside 1,600' - 810' ± - 26 Horizontal Alignment: Lower 21 00' 00" (R = 273') 30 mph* 26 42' 18" (R = 215') 25 mph Ramp: EB I-90 to WB SR-2 27 Horizontal Alignment: Lower 21 00' 00" (R = 273') 30 mph* R = 144' < 25 mph 28 Horizontal Alignment: Lower 21 00' 00" (R = 273') 30 mph* R = 264' 25 mph Ramp: WB I-90 from EB SR-2 29 Horizontal Alignment: Middle (Directional) 11 15' 00" (R = 509') 40 mph 34 43' 29" (R = 165') < 25 mph 30 Horizontal Alignment: Lower 21 00' 00" (R = 273') 30 mph* R = 262' 25 mph Ramp: WB I-90 from Lakeside 31 Acceleration Length (from stop) 960' - 75' ± - 32 Taper Rate 50:1-10:1 ± - Ramp: EB SR-2 to S. M. (Parking) 33 Horizontal Alignment: Lower 21 00' 00" (R = 273') 30 mph* R = 72' ± < 25 mph 34 Horizontal Alignment: Lower 21 00' 00" (R = 273') 30 mph* R = 77' ± < 25 mph Ramp: EB SR-2 from S. M. (Parking) 35 Acceleration Length (minimum) 850' - 270' ± - 36 Taper Rate 50:1-13:1 ± - Ramp: EB SR-2 to S. Marginal 37 Horizontal Alignment: Lower 21 00' 00" (R = 273') 30 mph* R = 55' ± < 25 mph 38 Horizontal Alignment: Lower 21 00' 00" (R = 273') 30 mph* R = 258' ± 25 mph Ramp: WB SR-2 to S. M. (Parking) Ramp: WB SR-2 from S.M. (Parking) 39 Horizontal Alignment: Lower 21 00' 00" (R = 273') 30 mph* R = 266' ± 25 mph 40 Deceleration Length 800' - 575' ± - 41 Horizontal Alignment: Lower 21 00' 00" (R = 273') 30 mph* R = 140' ± < 25 mph 42 Acceleration Length (minimum) 850' - 195' ± - 43 Taper Rate 50:1-13:1 ± - Totals: 44 *Rounded up from 28 mph per ODOT L&D Sec **ODOT Location and Design Manual Standards August 11, 2006 Page 4-15

16 Figure 4-6c: No-Build Alternative Weaving Sections Figure 4-6a Ref. No. Location Proposed Length Operational Performance (Acceptable / Deficient) Minimum Length Needed (if deficient) W1 EB I-90: From Superior to Lakeside 1,325' ± Acceptable N/A W2 EB I-90: From St. Clair to SR 2 2,400' ± Acceptable N/A W3 EB SR 2: From S. Marginal / Muni. Lot to I ' ± Acceptable N/A W4 WB I-90: From SR 2 to Superior 1,750' ± Acceptable N/A W5 WB I-90: From Lakeside to Superior 1,200' ± Acceptable N/A Total Number of Weaves: 5 Total Number Deficient Weaves: 0 August 11, 2006 Page 4-16

17 Figure 4-7a: Innerbelt Curve Alternative E Geometric Layout and Deficiencies August 11, 2006 Page 4-17

18 Figure 4-7b: Innerbelt Curve Alternative E Geometric Deficiencies Project Design Criteria Deficiencies Location Figure 4-7a Ref. No. Design Deficiency Standards** Design Speed Proposed Design Speed Ramp: EB I-90 to WB SR-2 1 Horizontal Alignment: Lower 21 00' (R = 273') 30 mph* 28 39' (R = 200') 25 mph Ramp: EB SR-2 to WB I-90 2 Horizontal Alignment: Middle (Directional) 11 15' 00" (R = 509') 40 mph 28 39' (R = 200') 25 mph Totals: 2 *Rounded up from 28 mph per ODOT L&D Sec **ODOT Location and Design Manual Standards Figure 4-7c: Innerbelt Curve Alternative E Weaving Sections Figure 4-7a Ref. No. Location Proposed Length Operational Performance (Acceptable / Deficient) Minimum Length Needed (if deficient) W1 WB I-90: From SR 2 to Superior 1,500' ± Acceptable N/A W2 WB I-90: From Superior to SR 2 2,300' ± Acceptable N/A Total Number of Weaves: 2 Total Number Deficient Weaves: 0 August 11, 2006 Page 4-18

19 Figure 4-8a: Innerbelt Curve Alternative F Geometric Layout and Deficiencies August 11, 2006 Page 4-19

20 Figure 4-8b: Innerbelt Curve Alternative F Geometric Deficiencies Project Design Criteria Deficiencies Location Figure 4-8a Ref. No. Design Deficiency Standards** Design Speed Proposed Design Speed Ramp: EB I-90 to WB SR-2 1 Horizontal Alignment: Lower 21 00' (R = 273') 30 mph* 28 39' (R = 200') 25 mph Totals: 1 *Rounded up from 28 mph per ODOT L&D Sec **ODOT Location and Design Manual Standards Figure 4-8c: Innerbelt Curve Alternative F Weaving Sections Figure 4-8a Ref. No. Location Proposed Length Operational Performance (Acceptable / Deficient) Minimum Length Needed (if deficient) W1 WB I-90: SR 2 to Superior 1,700' ± Acceptable N/A W2 EB I-90: Superior to SR 2 2,200' ± Acceptable N/A Total Number of Weaves: 2 Total Number Deficient Weaves: 0 August 11, 2006 Page 4-20

21 Figure 4-9: No-Build Alternative Level of Service August 11, 2006 Page 4-21

22 Figure 4-10: Innerbelt Curve Alternative E Level of Service August 11, 2006 Page 4-22

23 Figure 4-11: Innerbelt Curve Alternative F Level of Service August 11, 2006 Page 4-23