Request for Design Exception (#1) S.M. Wright Phase IIB

Request for Design Exception (#1) S.M. Wright Phase IIB County: Dallas CSJ s: 0092-01-059, 0092-14-088 Project Limits: From Pennsylvania Avenue to North of Al Lipscomb Way Date: June 28, 2016

Proposed Project The proposed S.M. Wright Phase IIB project includes improvements to IH 45 from Pennsylvania Avenue to north of Al Lipscomb Way (approximately 1 mile). The existing interchange between IH 45, S.M. Wright, Cesar Chavez Boulevard, and Good Latimer Expressway would be reconfigured under the proposed improvements, and the existing IH 45 frontage roads would be extended to Martin Luther King Jr. Boulevard (MLK). The existing ramps connecting IH 45 to MLK would be relocated to connect to the proposed MLK/frontage road intersection. Additional improvements to IH 45 include a northbound exit ramp to Al Lipscomb Way and a southbound entrance ramp from Al Lipscomb Way. To provide auxiliary lanes between the proposed ramps, the existing IH 45 bridge would be widened in both directions near the MLK overpass. The S.M. Wright Phase IIB project also proposes improvements to S.M. Wright for approximately 0.5 miles, from Pennsylvania Avenue to north of Al Lipscomb Way. The proposed project would connect S.M. Wright directly to Cesar Chavez Boulevard. Additionally, the existing S.M. Wright underpass of MLK would be converted to an at-grade signalized intersection. The connection between Edgewood St. and Good Latimer Expressway would also be eliminated. Similarly, Colonial Avenue would be reconfigured at the proposed southbound IH 45 frontage road/pennsylvania Avenue intersection. For a general location map of the proposed project, see Figure 1. Figure 1 - Project Location Map 2

Justification 1. *What are the minimum design values that cannot be attained? The 12-foot lane widths on IH 45 cannot be obtained. A minimum inside shoulder width of 10-feet on IH 45 cannot be obtained. A previous design exception (Appendix A) was requested and approved in 2012 for these design values which will be constructed as part of the SM Wright Phase I project. These widths will be existing conditions that will be unaffected by the SM Wright Phase IIB project. A technical memorandum (Appendix B) was developed to document minor revisions to the design exception after it had previously been approved. FHWA provided an approval letter (Appendix C) to document final approval of the SM Wright Phase I Design Exception. 2. Why can the minimum design values not be attained? The inside shoulder width and lane widths are existing conditions that will be constructed as part of the SM Wright Phase I project, currently under construction. These will remain in place upstream, adjacent to, and downstream of the proposed improvements associated with the SM Wright Phase IIB project. 3. What are the values that can be attained by the proposed design? Existing lane widths of 11 and an existing inside shoulder width of 2 will be maintained by the proposed design. 4. What is the accident history at this location? An accident analysis was conducted on IH 45 for the limits of the requested design exception. IH 45 Accident Analysis Within the Limits of the Requested Design Exception Crash data from 2010 through 2015 was analysed along IH 45 within the limits of the design exception, which is from Pennsylvania Avenue to South Boulevard (mile points 18.60-18.95). Table 1 below summarizes this data. Year Table 1 - Accidents Summary by Year along IH 45 within Limits of Design Exception Total Crashes Non- Serious / Serious * 2+ Vehicles (Rear End) 2+ Vehicles (Angle/Sdswipe) 1 Vehicle (Fixed Object) 1 Vehicle (Pedestrian) Veh. Mil. Traveled (100 Mil VMT) Crash Rate (per 100 Mil VMT) 2010 3 2/1 1 0 2 0 0.09 34.03 2011 3 2/1 1 1 1 0 0.09 35.05 2012 2 2/0 1 0 1 0 0.09 23.37 2013 0 0/0 0 0 0 0 0.09 0.00 2014 2 2/0 2 0 0 0 0.09 21.45 2015 9 9/0 4 3 2 0 0.09 96.51 Average 3.17 2.83/0.33 1.50 0.67 1.00 0.00 0.09 35.07 * Non-serious crashes include possibly injury, non-injury, and no information crashes. Serious crashes include fatal, incapacitating, and non-incapacitating crashes 3

Table 1 shows the ratio of serious to non-serious accidents, summarizes the accidents by type, gives the vehicle miles traveled, and analyzes crash rate for accidents along IH 45 between 2010 and 2015. The crash data recorded 19 accidents over the 6-year period of recordings along IH 45. A breakdown of accident type shows that 47% of these accidents consisted of 2+ vehicles in a rear end type collision, 21% consisted of 2+ vehicles in an angle/sideswipe collision, 32% consisted of 1 vehicle in a collision with a fixed object, and 0% consisted of 1 vehicle in a collision with a pedestrian. Of these 19 total recorded accidents, 89% (17 accidents) were considered non-serious while 11% (2 accidents) were considered serious. The accidents along IH 45 within the limits of the design exception were also analysed by day of the week. The results are shown in Table 2 below. The data shows accidents along IH 45 were spread fairly evenly throughout the week. Wednesday recorded the fewest accidents with 1 accident (5%) over the 6 year period while Tuesday and Thursday recorded the most accidents with 4 total accidents (21%). Table 2 - Accidents Summary by Day of Week along IH 45 within Limits of Design Exception Day Total Crashes Non-Serious / Serious * 2+ Vehicles (Rear End) 2+ Vehicles (Angle/Sdswipe) 1 Vehicle (Fixed Object) 1 Vehicle (Pedestrian) Monday 2 2/0 2 0 0 0 Tuesday 4 4/0 2 1 1 0 Wednesday 1 1/0 0 1 0 0 Thursday 4 3/1 2 1 1 0 Friday 3 3/0 2 0 1 0 Saturday 2 2/0 1 1 0 0 Sunday 3 2/1 0 0 3 0 Total 19 17/2 9 4 6 0 * Non-serious crashes include possibly injury, non-injury, and no information crashes. Serious crashes include fatal, incapacitating, and non-incapacitating crashes. IH 45 Accident Analysis Comparative Data Texas statewide traffic crash rates for urban interstates have been provided in Table 3 below for the comparative years of 2010 through 2015. Based on this data, the 6-year average crash rate for an urban interstate in Texas is 93.07 crashes per 100 million vehicle miles travelled. The accident summary along IH 45 within the limits of the design exception recorded an average crash rate of 35.07 crashes per 100 million vehicle miles travelled, which is approximately 62% lower than the Texas statewide average over the same time period. 4

Table 3 - Statewide Traffic Crash Rates for Urban Interstates Year Traffic Crashes per 100 Mil VMT 2010 76.99 2011 70.21 2012 94.14 2013 99.44 2014 108.82 2015 108.82 Average 93.07 A Texas Roadway Safety Design (TRSD) analysis was performed on IH 45 to predict the number of expected crashes based on the proposed roadway geometry as compared to standard roadway geometry that meets or exceeds minimum design criteria. The TRSD results, provided in Appendix D, predicted approximately 19.47 serious crashes per year for design year 2040 on IH 45 within the limits of the design exception (for 11 lanes and 2 inside shoulder). The same software predicted approximately 16.10 serious crashes per year for 2040 on a facility that maintained 12 lanes and a 10 inside shoulder. The results show an increase of approximately 3.37 predicted serious crashes per year for the reduced lane and inside shoulder widths on IH 45. 5. Brief description of alternatives considered and the reasons for eliminating each alternative. Several alternatives regarding the reconstruction or widening of IH 45 were developed and evaluated during the SM Wright Phase I project. These alternatives are listed below: Build Alternative #1 Widen and Maintain the Existing Alignment An alternative of maintaining the existing mainlane alignment, pavement, and bridges along with outside widening was considered. This alternative would provide four 12-foot lanes (each direction) and 10-foot inside and outside shoulders. Widening about the centerline of IH 45 would require additional ROW and impact properties located within the Colonial Hill Historic District east of IH 45. As discussed above, this historic district is listed on the National Register of Historic Places and is considered a 4(f) resource. North of Pennsylvania Avenue, IH 45 is entirely on bridge. Outside widening of the existing bridge would require a design exception for minimum vertical clearance at 4 overpass locations between Pennsylvania Avenue and South Boulevard. Harwood Street would need to be realigned to fit between the extensions of existing bent locations. Widening the existing IH 45 bridge north of Pennsylvania Avenue would also require reconstructing the existing northbound entrance from S.M. Wright Freeway. This alternative was eliminated due to the potential ROW impacts and environmental constraints associated with the Colonial Hill Historic District. 5

Build Alternative #2 Widen and Reconstruct IH 45 on New Alignment In order to not impact the historic district, IH 45 would need to be widened to the west side from Lamar Street to north of Pennsylvania Avenue. This westerly widening would require complete reconstruction of the mainlanes, southbound frontage road, ramps, and a pedestrian bridge since the existing alignment would no longer be maintained. West of IH 45, it would require the acquisition of ROW from residences, businesses, and potentially a school as well as displace structures on some of these properties. North of the Pennsylvania Avenue overpass, the existing alignment could be maintained. However, maintaining desirable minimum vertical clearances over under passing roadways would require reconstructing the mainlane bridges and raising the profile from Pennsylvania Avenue to south of the existing S.M. Wright interchange. This alternative would require a substantial increase in the construction cost when compared with the proposed design. Due to existing funding constraints, this additional cost could indefinitely delay construction of the S.M. Wright project proposed improvements. No Build Alternative The Metropolitan Transportation Plan (MTP): Mobility 2035 is the current long-range transportation plan for the Dallas-Fort Worth Area. FHWA has determined that this plan meets all requirements for making a joint conformity determination under the Clean Air Act Amendments of 1990. Improvements associated with the S.M. Wright project are included in the Mobility 2035 plan and are scheduled to be open to traffic before 2020. A no build alternative was considered but was eliminated as it fails to comply with Mobility 2035 plan. The no build alternative does not address safety concerns associated with the existing US 175 geometry and does not address decisions and concerns expressed by the public and local policy makers. 6. What are the percentage and total dollar difference between the proposed construction cost and the cost of construction necessary to obtain minimum values? The proposed construction cost for the IH 45 improvements of SM Wright Phase IIB are approximately $23 million. As discussed in the SM Wright Phase I Design Exception, the construction cost to maintain minimum design values would cost an additional $37 million (excluding ROW, utility relocation and engineering costs). The cost difference to meet the minimum desired lane widths and shoulder widths would result in an approximate increase of 161% to the IH 45 construction costs. 7. Does the design conform with adjacent roadway sections? The limits of this design exception, which are existing conditions, extend beyond the limits of this project; therefore, the design does conform with adjacent roadway sections. 8. What would be the project delay and consequences as a result of meeting the minimum values? There is a substantial cost differential to construct IH 45 to meet minimum values. Due to this large cost differential, the SM Wright Phase I project received approval for these less than desirable design values. If the SM Wright Phase IIB project had to meet the minimum values, it would likely exceed any available funding for the project. If this occurred, SM Wright Phase II is expected to be constructed as a stand-alone project without incorporating SM Wright Phase IIB. 6

9. Short narrative of why you feel this design exception should be approved. TxDOT is moving forward with the SM Wright Project Phase I project (currently under construction) which creates a new IH 45 / US 175 interchange approximately 1.2 miles south of the existing interchange. SM Wright Phase II has received schematic approval and environmental clearance and is expected to be constructed as soon as Phase I is completed. Phase II will reconstruct SM Wright from a controlled-access freeway between IH 45 and US 175 to a six-lane divided arterial street that will be removed from TxDOT s roadway system. The Environmental Assessment for the overall SM Wright Project (Phases I and II) received a FONSI on September 13, 2013. SM Wright Phase IIB will provide better local access connectivity and circulation in the area. The project will provide the new access ramps that were committed to by TxDOT during the previous Environmental Document (Phases I and II). The revised access points and proposed improvements are consistent with the policies and goals set forth by NCTCOG in Mobility 2035 2014 Amendment. The proposed improvements are also incorporated in all improvement plans for TxDOT and FHWA. The proposed project is currently included in the 2015-2018 Transportation Improvement Program for North Central Texas. The project is also supported by the City of Dallas and adjacent neighbourhoods. No other future interchanges with IH 45 are proposed within or adjacent to the study area. The proposed improvements are significant improvements to the existing no build conditions and meet the purpose of providing additional access to the area. Furthermore, the proposed improvements do not have significant impacts to the operations and safety on the interstate. Design Exceptions for the inside shoulder width and lane widths were requested and approved as part of the SM Wright Phase I project. The SM Wright Phase IIB project will not affect these existing conditions; therefore, we feel these design exceptions should be approved, as previously proposed (and approved) with the SM Wright project. 7

APPENDIX A SM Wright Phase I Design Exception

S.M. Wright Project REQUEST FOR DESIGN EXCEPTION Number 1 County: Dallas CSJ's: 0092-01-052, 0197-02-108, 0092-14-081 Project: S.M. Wright Project Project Limits: US 175 from east of Bexar Street to IH 45 SH 310 from north of Budd Street to US 175 IH 45 from south of Lamar Street to US 175 Proposed Project The proposed S.M. Wright Project would include constructing improvements to IH 45 from existing S.M. Wright Freeway (US 175) to south of Lamar Street (2.3 miles); S.M. Wright Freeway (US 175/SH 310) from IH 45 to north of Budd Street (2.2 miles); and C.F. Hawn Freeway (US 175) from east of Bexar Street to IH 45 (1.5 miles), which would include the construction of a new interchange with IH 45. For clarification purposes, existing US 175 is named S.M. Wright Freeway from the existing IH 45 interchange to SH 310. Existing S.M. Wright Freeway includes segments of US 175 and SH 310. Existing US 175 is named C.F. Hawn Freeway south and east of SH 310. The proposed improvements would include converting S.M. Wright Freeway from an existing six - lane freeway to a low speed, signalized six-lane urban arterial. The existing S.M. Wright ramp access at IH 45 would be maintained, and the northbound entrance ramp to IH 45 would be restriped from two lanes to one lane. The gore at the existing two lane southbound exit ramp from IH 45 to S.M. Wright would be restriped from a two lane drop on IH 45 to a one lane drop plus an optional exit to the second ramp lane. Associated improvements would include extending proposed C.F. Hawn Freeway (US 175) westerly to overpass the proposed S.M. Wright parkway and Lamar Street. The C.F. Hawn frontage roads would be extended to Lamar Street to facilitate local access. The extension of C.F. Hawn Freeway (US 175) westerly would include constructing two-lane direct connecting (DC) ramps from northwest bound C.F. Hawn Freeway (US 175) to northbound IH 45 and two-lane DC ramps from southbound IH 45 to southeast bound C.F. Hawn Freeway (US 175). Upstream of the proposed DC ramp junctions, IH 45 would be widened to the inside to allow for the addition of a transition lane. This additional lane (each direction) would serve as a transition between the proposed C.F. Hawn Freeway and the existing IH 45 five lane section north of the existing S.M. Wright interchange. From south of Martin Luther King Jr. Boulevard to Lamar Street, existing IH 45 utilizes a double sided metal beam guard fence as the median barrier. The proposed project would replace this existing barrier with a concrete traffic barrier. Providing a direct link between IH 45 and C.F. Hawn Freeway (US 175) would remove freeway/commuter traffic from the communities adjacent to the S.M. Wright corridor and would improve the neighborhood environment. The proposed improvements would also eliminate the sharp, accident-prone curve along US 175 that currently connects C.F. Hawn Freeway and S.M. Wright Freeway. Page 1 of 13

S.M. Wright Project Justification 1. What are the minimum design values that cannot be attained? The 12-foot lane widths on IH 45 cannot be obtained. The minimum inside shoulder width of 10-feet on IH 45 cannot be obtained. 2. Why can the minimum design values not be attained? The study portion of IH 45 was constructed in the late 1960's to early 1970's. Existing IH 45 is a 6- lane urban freeway from the southern project limits south of Lamar Street to the interchange with existing US 175 (S.M. Wright Freeway). The existing interchange between IH 45 and US 175 consists of a northbound 2-lane DC entrance ramp from US 175 and a southbound 2-lane DC exit ramp to US 175. North of the existing US 175 interchange, IH 45 is a 10-lane section (6 mainlanes/ 4 auxiliary lanes) up to the southern half of the IH 30 interchange. North of the northbound exit to IH 30 and southbound entrance from IH 30, IH 45 returns to a 6-lane section. The IH 45 mainlanes are on structure from the southern project limits to Lamar Street and from Martin Luther King Jr. Boulevard to the northern project limits. The mainlanes consist of 12-foot wide travel lanes with 10-foot wide inside and outside shoulders. Existing frontage roads are present between Lamar Street and Pennsylvania Avenue. Identified deficiencies in the current roadway configuration include insufficient weaving distance between the US 175 and IH 30 DC ramps. The existing configuration provides approximately 2,400-feet (northbound) and 1,500-feet (southbound) of weaving distance between these DC ramps. These distances are insufficient to facilitate weaving volumes between the mainlanes and DC ramps, which negatively impacts traffic operations on IH 45. The Colonial Hill Historic District is located east of IH 45, and is directly adjacent to the existing IH 45 northbound frontage road from north of Lamar Street to Pennsylvania Avenue. This historic district is listed on the National Register of Historic Places and is considered a 4(f) resource. The proposed DC ramps between C.F. Hawn Freeway (US 175) and IH 45 would connect to the IH 45 mainlanes in the vicinity of the Lamar Overpass. The addition of these DC ramps would require adding a fourth transition lane in each direction from the DC gores up to the existing S.M. Wright interchange ramp gores, a distance of approximately 7,000-feet. Widening about the centerline of IH 45 would require additional right-of-way (ROW) and impact properties located within the Colonial Hill Historic District east of IH 45. Widening about the centerline would also require vertical clearance design exceptions at multiple overpass locations. A westerly widening would avoid the historic district and increase vertical clearances, but would require significant reconstruction of the mainlanes, frontage roads, and ramps since the existing alignment would no longer be maintained. A westerly widening would also require additional ROW from residences, businesses, and a school. Reconstruction of a pedestrian bridge would also be required. This reconstruction and widening of IH 45 to utilize 12-foot travel lanes and 10-foot inside and outside shoulders would increase the project cost substantially. Due to existing funding constraints, this additional cost would indefinitely delay construction of the proposed improvements. Page 2 of 13

S.M. Wright Project 3. What are the values that can be attained by the proposed design? The minimum values listed below would be applicable along IH 45 for approximately 1.2 miles along the northbound mainlanes and 1.5 miles along the southbound mainlanes (from south of Lamar Street to north of the S.M. Wright interchange): A 2-foot wide inside shoulder measured from the nominal face of the median CTB to the inside lane line on IH 45. 11-foot wide mainlanes along IH 45. 10-foot wide outside shoulder along IH 45. The remainder of IH 45 within the S.M. Wright project limits would not require a design exception for lane or shoulder widths. 4. What is the accident history at this location? As previously discussed, the project would relocate the existing US 175 interchange with IH 45 further south. This would eliminate the sharp, accident-prone curve along US 175 that currently connects C.F. Hawn Freeway and S.M. Wright Freeway. It would also increase the IH 45 weaving distance between the proposed US 175 interchange and the existing IH 30 interchange. Therefore, the accident analysis of IH 45 has been broken down into two segments which include the limits of the requested design exception and the weaving segment north of the existing US 175 interchange. An analysis of US 175 at the existing connection between S.M. Wright Freeway and C.F. Hawn Freeway has also been provided. IH 45 Accident Analysis Within the Limits of the Requested Design Exception Crash data from 2007 through 2010 was analyzed along IH 45 within the limits of the design exception, which is from south of Lamar Street to north of the existing S.M. Wright interchange (mile points 18.060-19.525). Table 1 below summarizes this data. Year Table 1 Accidents Summary by Year along IH 45 within Limits of Design Exception 2+ Veh. Mil. Non- 2+ Vehicles 1 Vehicle Crash Rate Total Vehicles 1 Vehicle Traveled Serious / (Angle/ (Fixed Crashes (Rear (Pedestrian) (100 Mil (per 100 Mil Serious * Sdswipe) Object) End) VMT) VMT) 2007 34 32/2 11 11 12 0 0.41 83.19 2008 49 45/4 14 21 14 0 0.40 123.11 2009 45 34/11 11 16 16 2 0.39 116.26 2010 60 53/7 20 25 14 1 0.39 154.69 Total 188 164/24 56 73 56 3 1.58 477.25 Average 47 41/4 14 18 14 1 0.40 119.31 * Non-serious crashes include possibly injury, non-injury, and no information crashes. Serious crashes include fatal, incapacitating, and non-incapacitating injury crashes. Table 1 shows the ratio of serious to non-serious accidents, summarizes the accidents by type, gives the vehicle miles traveled, and analyzes crash rate for accidents along IH 45 between 2007 and 2010. Page 3 of 13

S.M. Wright Project The crash data recorded 188 accidents over the 4-year period of recordings along IH 45. A breakdown of accident type shows that 30% of these accidents consisted of 2+ vehicles in a rear end type collision, 39% consisted of 2+ vehicles in an angle/sideswipe collision, 30% consisted of 1 vehicle in a collision with a fixed object, and 1% consisted of 1 vehicle in a collision with a pedestrian. Of these 188 total recorded accidents, 87% (164 accidents) were considered non-serious while 13% (24 accidents) were considered serious. The accidents along IH 45 within the limits of the design exception were also analyzed by day of week. The results are shown in Table 2 below. The data shows accidents along IH 45 were spread fairly evenly throughout the week. Thursday recorded the fewest accidents with 22 total accidents (12%) over the 4 year period while Saturday recorded the most accidents with 32 total accidents (17%). Table 2 Accidents Summary by Day of Week along IH 45 within Limits of Design Exception 1 Vehicle Total Non-Serious / 2+ Vehicles 2+ Vehicles 1 Vehicle Day (Fixed Crashes Serious * (Rear End) (Angle/Sdswipe) (Pedestrian) Object) Monday 25 21/4 4 11 9 1 Tuesday 29 28/1 9 17 3 0 Wednesday 27 26/1 7 13 7 0 Thursday 22 19/3 7 6 9 0 Friday 25 21/4 10 8 6 1 Saturday 32 27/5 12 9 11 0 Sunday 28 22/6 7 9 11 1 Total 188 164/24 56 73 56 3 Average 27 23/3 8 10 8 < 1 * Non-serious crashes include possibly injury, non-injury, and no information crashes. Serious crashes include fatal, incapacitating, and non-incapacitating injury crashes. In Table 3 below, the accidents along IH 45 within the limits of the design exception were analyzed by time of day. The AM and PM peak hours combined account for 6 hours (25%) of every day. These combined peak periods account for approximately 33% of total crashes, which is fairly proportionate to the time period. The severity of accidents was also fairly proportionate to the time period. The results show there was a larger proportion (41%) of rear end accidents during the peak hour time frames. Time ** Table 3 Accidents Summary by Time of Day along IH 45 within Limits of Design Exception Total Crashes Non-Serious / Serious * 2+ Vehicles (Rear End) Page 4 of 13 2+ Vehicles (Angle/Sdswipe) 1 Vehicle (Fixed Object) 1 Vehicle (Pedestrian) AM Peak 31 25/6 14 9 8 0 PM Peak 31 28/3 9 15 7 0 Off Peak 126 111/15 33 49 41 3 Total 188 164/24 56 73 56 3 * Non-serious crashes include possibly injury, non-injury, and no information crashes. Serious crashes include fatal, incapacitating, and non-incapacitating crashes. ** AM Peak from 6:00 AM - 9:00 AM, PM Peak from 4:00 PM - 7:00 PM

S.M. Wright Project IH 45 Accident Analysis Weaving Segment between the S.M. Wright and IH 30 Interchanges Crash data from 2007 through 2010 was also analyzed along 0.34 miles of IH 45 at the 10-lane weaving segment starting at the northern limit of the design exception and ending at the IH 30 DC ramps (mile points 19.525-19.867). Table 4 below summarizes this data. Year Table 4 Accidents Summary by Year along IH 45 at 10-Lane Weaving Segment Non- 2+ 1 Veh. Mil. 2+ Vehicles Total Serious / Vehicles Vehicle 1 Vehicle Traveled (Angle/ Crashes Serious (Rear (Fixed (Pedestrian) (100 Mil Sdswipe) * End) Object) VMT) Crash Rate (per 100 Mil VMT) 2007 11 9/2 3 8 0 0 0.18 62.50 2008 6 5/1 2 2 1 1 0.17 34.58 2009 13 12/1 3 6 4 0 0.17 76.57 2010 27 22/5 4 14 9 0 0.17 155.61 Total 57 48/9 12 30 14 1 0.69 329.26 Average 14 12/2 3 8 4 < 1 0.17 82.31 * Non-serious crashes include possibly injury, non-injury, and no information crashes. Serious crashes include fatal, incapacitating, and non-incapacitating crashes. The crash data recorded 57 accidents over the 4-year period of recordings along the weaving segment of IH 45. A breakdown of accident type shows that 21% of these accidents consisted of 2+ vehicles in a rear end type collision, 53% consisted of 2+ vehicles in an angle/sideswipe collision, 25% consisted of 1 vehicle in a collision with a fixed object, and 1% consisted of 1 vehicle in a collision with a pedestrian. This weaving segment of IH 45 has a higher percentage of sideswipe/angle collision when compared to the existing 6-lane segment within the design exception limits. Of the 57 total recorded accidents, 84% (48 accidents) were considered non-serious while 16% (9 accidents) were considered serious. The accident summary along IH 45 within the 10-lane weaving segment recorded an average crash rate of 82.31 crashes per 100 million vehicle miles traveled. This relatively low crash rate is a result of the approximate 68,000 average daily traffic (ADT) that is added to IH 45 between the IH 30 and US 175 interchanges. This additional traffic between these two interchanges increases the IH 45 mainlane volumes to an approximately 139,000 ADT average over the 4-year analysis period within a relatively short analysis length of 0.34 miles. The accidents along IH 45 the 10-lane weaving segment were also analyzed by day of week. The results are shown in Table 5 below. The data shows a noticeably higher number of accidents for Friday and Saturday when compared to the remaining weekdays. Friday and Saturday combined accounted for 47% of the total accidents recorded in the 4-year period. Page 5 of 13

S.M. Wright Project Table 5 Accidents Summary by Day of Week along IH 45 at 10-Lane Weaving Segment Day Total Crashes Non-Serious / Serious * 2+ Vehicles (Rear End) 2+ Vehicles (Angle/Sdswipe) 1 Vehicle (Fixed Object) 1 Vehicle (Pedestrian) Monday 8 6/2 4 4 0 0 Tuesday 5 4/1 0 4 1 0 Wednesday 5 5/0 0 2 3 0 Thursday 7 6/1 2 3 2 0 Friday 16 13/3 4 9 3 0 Saturday 11 9/2 1 7 2 1 Sunday 5 5/0 1 1 3 0 Total 57 48/9 12 30 14 1 Average 8 7/1 2 4 2 < 1 * Non-serious crashes include possibly injury, non-injury, and no information crashes. Serious crashes include fatal, incapacitating, and non-incapacitating crashes. In Table 6 below, the accidents along the IH 45 10-lane weaving segment were also analyzed by time of day. The results show the number of accidents was spread fairly evenly throughout the day; however, the severity of accidents fluctuated. The results show there were no serious accidents during the peak hour time frames while there were 9 serious accidents during the off-peak hour time frames. The severity of accidents is often relative to the speed of the vehicles in the accidents. With the large amount of traffic in this weaving segment, traffic is often congested during the peak hours resulting in lower speeds. These lower speeds during the peak hours could result in more non-serious accidents and fewer serious accidents. Table 6 Accidents Summary by Time of Day along IH 45 at 10-Lane Weaving Segment Time ** Total Crashes Non-Serious / Serious * 2+ Vehicles (Rear End) 2+ Vehicles (Angle/Sdswipe) 1 Vehicle (Fixed Object) 1 Vehicle (Pedestrian) AM Peak 7 7/0 3 3 1 0 PM Peak 8 8/0 3 4 1 0 Off Peak 42 33/9 6 23 12 1 Total 57 48/9 12 30 14 1 * Non-serious crashes include possibly injury, non-injury, and no information crashes. Serious crashes include fatal, incapacitating, and non-incapacitating crashes. ** AM Peak from 6:00 AM - 9:00 AM, PM Peak from 4:00 PM - 7:00 PM IH 45 Accident Analysis Comparative Data Texas statewide traffic crash rates for urban interstates have been provided in Table 7 below for the comparative years of 2007 through 2010. Based on this data, the 4-year average crash rate for an urban interstate in Texas is 102.21 crashes per 100 million vehicle miles traveled. The accident summary Page 6 of 13

S.M. Wright Project along IH 45 within the limits of the design exception recorded an average crash rate of 119.31 crashes per 100 million vehicle miles traveled, which is approximately 17% higher than the Texas statewide average over the same time period. The 10-lane weaving segment between the existing IH 30 and S.M. Wright interchanges recorded an average crash rate of 82.31 crashes per 100 million vehicle miles traveled, which is approximately 19% lower than the Texas statewide average over the same time period. Table 7 Texas Statewide Traffic Crash Rates for Urban Interstates Year Traffic Crashes per 100 Mil VMT 2007 111.08 2008 101.15 2009 99.27 2010 97.34 Average 102.21 A Texas Roadway Safety Design (TRSD) analysis was performed on IH 45 to predict the number of expected crashes based on the existing roadway geometry and to establish a baseline for the expected safety performance of existing IH 45 within the study limits. As shown in Table 8 below, the TRSD analysis predicted the 6-lane segment of IH 45 within the limits of the design exception would have approximately 17 serious crashes per year and the 10-lane weaving segment of IH 45 would have approximately 3 serious crashes per year. The accident data from 2007 to 2010 recorded an average of 6 accidents per year on the 6-lane segment of IH 45 within the limits of the design exception and an average of 2.25 serious accidents per year on the 10-lane weaving segment of IH 45. Both values are less than the predicted number of crashes from the TRSD Analysis. Table 8 TRSD Analysis for Serious Crashes IH 45 Segment Predicted # of Serious Crashes 6-Lane Segment (Design Exception Limits) 17.18 10-Lane Weaving Segment 2.91 US 175 Accident Analysis Existing C.F. Hawn Freeway and S.M. Wright Freeway Interchange As previously discussed, the proposed improvements would realign US 175 westerly to construct a new interchange with IH 45. This realignment would in turn remove the 90 degree bend in the US 175 alignment that currently connects the C.F. Hawn Freeway segment of US 175 to the S.M. Wright Freeway segment of US 175. Crash data from 2007 through 2010 was also analyzed on US 175 within the limits of the existing S.M. Wright / C.F. Hawn interchange, which includes the 90 degree bend in mainlane alignment up to the connection between the two roadways (approximately 0.23 miles). The results are shown below in Table 9. Page 7 of 13

S.M. Wright Project Year Table 9 Accidents Summary by Year within the existing S.M. Wright/C.F. Hawn Interchange Non- 2+ 1 Veh. Mil. Crash 2+ Vehicles Total Serious / Vehicles Vehicle 1 Vehicle Traveled Rate (Angle/ Crashes Serious (Rear (Fixed (Pedestrian) (100 Mil (per 100 Sdswipe) * End) Object) VMT) Mil VMT) 2007 6 6/0 1 2 3 0 0.07 85.08 2008 10 7/3 2 6 2 0 0.07 138.51 2009 11 9/2 4 3 3 1 0.07 161.77 2010 15 11/4 2 4 8 1 0.07 217.90 Total 42 33/9 9 15 16 2 0.28 603.26 Average 11 8/2 4 4 4 < 1 0.07 150.82 * Non-serious crashes include possibly injury, non-injury, and no information crashes. Serious crashes include fatal, incapacitating, and non-incapacitating crashes. The accident summary recorded a total of 42 accidents over the 4-year recording period and an average crash rate of 150.82 crashes per 100 million vehicle miles traveled on US 175 within the limits of the existing S.M. Wright / C.F. Hawn interchange. The analysis shows that every year for the analysis period the crash rate has increased by an average of 44.27 crashes per 100 million vehicle miles travelled within the limits of the S.M. Wright and C.F. Hawn interchange, with a 2010 crash rate of 217.90 crashes per 100 million vehicle miles travelled in 2010. The analysis also shows that: 21% of the accidents consisted of 2+ vehicles in a rear end type collision; 36% of the accidents consisted of 2+ vehicles in an angle/sideswipe collision; 38% of the accidents consisted of 1 vehicle in a collision with a fixed object; and 5% of the accidents consisted of 1 vehicle in a collision with a pedestrian. Of these 42 total accidents, 79% were considered non-serious while 21% were considered serious. Table 10 below analyzes the accidents within the existing S.M. Wright / C.F. Hawn interchange by day of week. The data shows a marked increase in overall accidents, rear end accidents, and angle/sideswipe accidents on Wednesdays, Thursdays, and Fridays. Table 10 Accidents Summary by Day of Week within the existing S.M. Wright/C.F. Hawn Interchange Day Total Crashes Non-Serious / Serious * 2+ Vehicles (Rear End) 2+ Vehicles (Angle/Sdswipe) 1 Vehicle (Fixed Object) 1 Vehicle (Pedestrian) Monday 4 3/1 2 1 1 0 Tuesday 4 3/1 0 1 3 0 Wednesday 12 9/3 3 6 3 0 Thursday 9 9/0 2 5 2 0 Friday 7 5/2 2 1 3 1 Saturday 3 2/1 0 0 3 0 Sunday 3 2/1 0 1 1 1 Total 42 33/9 9 15 16 2 Average 6 5/1 1 2 2 < 1 * Non-serious crashes include possibly injury, non-injury, and no information crashes. Serious crashes include fatal, incapacitating, and non-incapacitating crashes. Page 8 of 13

S.M. Wright Project Table 11 below analyzes the accidents within the existing S.M. Wright / C.F. Hawn interchange by time of day. The AM and PM peak hours combined account for 6 hours (25%) of every day. These combined peak periods account for approximately 33% of total crashes, which is fairly proportionate to the time period. The severity of accidents was also fairly proportionate to the time period. The results show there was a disproportionate amount of rear end accidents (67%) and angle/sideswipe accidents (40%) during the peak hour time frames. This could be representative of congested conditions that occur in the vicinity of the interchange during peak periods. For the off peak hour time frame, there was a disproportionate amount of 1 vehicle fixed object accidents (94%). This could be representative of vehicle traveling in non-congested, time periods at a rate of speed that is too high to safely traverse the 90 degree bend in the alignment. Table 11 Accidents Summary by Tim of Day within the existing S.M. Wright/C.F. Hawn Interchange Non- Total 2+ Vehicles 2+ Vehicles 1 Vehicle 1 Vehicle Time ** Serious / Crashes (Rear End) (Angle/Sdswipe) (Fixed Object) (Pedestrian) Serious * AM Peak 6 5/1 2 3 0 1 PM Peak 8 7/1 4 3 1 0 Off Peak 28 21/7 3 9 15 1 Total 42 33/9 9 15 16 2 * Non-serious crashes include possibly injury, non-injury, and no information crashes. Serious crashes include fatal, incapacitating, and non-incapacitating crashes. ** AM Peak from 6:00 AM - 9:00 AM, PM Peak from 4:00 PM - 7:00 PM 5. Brief description of alternatives considered and the reasons for eliminating each alternative. Build Alternative #1 Widen and Maintain the Existing Alignment An alternative of maintaining the existing mainlane alignment, pavement, and bridges along with outside widening was considered. This alternative would provide four 12-foot lanes (each direction) and 10-foot inside and outside shoulders. Widening about the centerline of IH 45 would require additional ROW and impact properties located within the Colonial Hill Historic District east of IH 45. As discussed above, this historic district is listed on the National Register of Historic Places and is considered a 4(f) resource. North of Pennsylvania Avenue, IH 45 is entirely on bridge. Outside widening of the existing bridge would require a design exception for minimum vertical clearance at 4 overpass locations between Pennsylvania Avenue and South Boulevard. Harwood Street would need to be realigned to fit between the extensions of existing bent locations. Widening the existing IH 45 bridge north of Pennsylvania Avenue would also require reconstructing the existing northbound entrance from S.M. Wright Freeway. This alternative was eliminated due to the potential ROW impacts and environmental constraints associated with the Colonial Hill Historic District. Build Alternative #2 Widen and Reconstruct IH 45 on New Alignment In order to not impact the historic district, IH 45 would need to be widened to the west side from Lamar Street to north of Pennsylvania Avenue. This westerly widening would require complete reconstruction of the mainlanes, southbound frontage road, ramps, and a pedestrian bridge since the existing alignment would no longer be maintained. West of IH 45, it would require the acquisition Page 9 of 13

S.M. Wright Project of ROW from residences, businesses, and potentially a school as well as displace structures on some of these properties. North of the Pennsylvania Avenue overpass, the existing alignment could be maintained. However, maintaining desirable minimum vertical clearances over under passing roadways would require reconstructing the mainlane bridges and raising the profile from Pennsylvania Avenue to south of the existing S.M. Wright interchange. This alternative would require a substantial increase in the construction cost when compared with the proposed design. Due to existing funding constraints, this additional cost could indefinitely delay construction of the S.M. Wright project proposed improvements. No Build Alternative The Metropolitan Transportation Plan (MTP): Mobility 2035 is the current long-range transportation plan for the Dallas-Fort Worth Area. FHWA has determined that this plan meets all requirements for making a joint conformity determination under the Clean Air Act Amendments of 1990. Improvements associated with the S.M. Wright project are included in the Mobility 2035 plan and are scheduled to be open to traffic before 2020. A no build alternative was considered but was eliminated as it fails to comply with Mobility 2035 plan. The no build alternative does not address safety concerns associated with the existing US 175 geometry and does not address decisions and concerns expressed by the public and local policy makers. 6. What are the percentage and total dollar difference between the proposed construction cost and the cost of construction necessary to obtain minimum values? The proposed construction cost for the IH 45 improvements associated with the S.M. Wright project is approximately $17 million. The construction cost for alternative #2 which would maintain minimum design values would cost approximately $54 million (excluding ROW, utility relocation, and engineering costs). This cost difference of $37 million to meet the minimum desired lane widths and shoulder widths would result in an approximate increase of 218% to the IH 45 construction costs and an increase of approximately 31% to the total project construction costs ($119 million). 7. Does this design conform with adjacent roadway sections? The sections of IH 45 adjacent to the proposed project maintain 12-foot mainlanes and 10-foot inside and outside shoulders, which differs from the proposed 11-foot mainlanes and 2-foot inside shoulder. However, the proposed design does conform to adjacent roadway sections in terms of lane balance. At the north IH 45 project limit, the existing northbound S.M. Wright to IH 45 2-lane entrance ramp would be restriped to a 1-lane entrance ramp with a 1-lane add to IH 45 to match the existing 5-lane northbound section. The reduction in capacity of this northbound entrance ramp is possible because US 175 traffic entering IH 45 would be removed from this ramp and placed on the proposed northbound C.F. Hawn Freeway (US 175) to IH 45 DC ramp. The existing 2-lane exit ramp from southbound IH 45 to S.M. Wright would be maintained and striped so that the fifth IH 45 mainlane would be dropped at this ramp. At the south IH 45 project limit, the proposed C.F. Hawn Freeway (US 175) / IH 45 DC ramps would serve as a lane add and drop. IH 45 would remain a 6-lane facility (3- lanes each direction) south of these proposed DC ramps. Transitions between existing and proposed mainlane and inside shoulder widths would occur at the two interchanges discussed above. Page 10 of 13

S.M. Wright Project 8. What would be the project delay and consequences as a result of meeting the minimum values? There is sufficient funding to construct the project as proposed. However, there are currently no additional funds available that could be applied to the project. The substantial cost differential to construct IH 45 to meet minimum values is stated above. Current funding availability and constraints could conceivable delay the project indefinitely. 9. Short narrative of why you feel this design exception should be approved. Project Benefits The proposed design exception for IH 45 shoulder and lane widths would allow for the connection of new DC ramps between US 175 and IH 45 by facilitating the lane balance needed along IH 45. These proposed DC ramps would provide the following benefits. In the existing configuration, US 175 connects to IH 45 at the S.M. Wright interchange. This creates a weaving section between the US 175 and IH 30 ramps of approximately 1,500-feet (southbound) to 2,400-feet (northbound). This relatively short weaving segment is operationally constrained. Analysis of crash data from 2007 to 2010 shows that approximately 48% of the total accidents located within the design exception limits (1.5 miles long) occur within 2,600-feet of the S.M. Wright interchange. Further breakdown shows that 59% of the total rear-end accidents located within the design exception limits occur within 2,600-feet of the S.M. Wright interchange. It is reasonable to assume that the constrained operations of the weaving segment between the S.M. Wright and IH 30 interchanges play a factor in the occurrence of these accidents. Adding the proposed DC ramps between C.F. Hawn Freeway (US 175) and IH 45 would increase the weaving distance between US 175 and IH 30 to approximately 8,600-feet (southbound) and 8,000-feet (northbound). This increased distance would improve weaving operations on IH 45. Realigning C.F. Hawn Freeway (US 175) and constructing a new interchange with IH 45 would eliminate the sharp, accident-prone curve along US 175 that currently connects C.F. Hawn Freeway and S.M. Wright Freeway. This would in turn improve safety on US 175. In 2008, a gasoline tanker truck travelling along US 175 did not successfully traverse the 90 degree bend in the mainlane alignment. The explosion from the tanker crash required shutting down the interchange and reconstructing the SH 310 (S.M. Wright Freeway) bridge that overpasses US 175. The safety analysis performed in Section 4 shows that from 2007 through 2010 the crash rate increased every year by an average of 44.27 crashes per 100 million vehicle miles travelled within the limits of the S.M. Wright and C.F. Hawn interchange. The 2010 crash rate was recorded at 217.90 crashes per 100 million vehicle miles travelled. If the crash rate continues to increase by this average, the crash rate will exceed 350 crashes per 100 million vehicle miles travelled by the proposed construction letting date in 2014. This new interchange would allow traffic traveling between US 175 and IH 45 to bypass the S.M. Wright corridor. It would also facilitate the downsizing of S.M. Wright from a freeway to a local arterial, thereby reconnecting the adjacent residential communities and improving neighborhood environment. Page 11 of 13

S.M. Wright Project Previous Studies/Guidance REPORT NO. FHWA/TX-87/32+395-1: A 1987 technical report by the Texas Transportation Institute titled Safety and Operational Evaluation of Shoulders on Urban Freeways analyzed the safety and traffic operations performance of reducing inside shoulder widths and lane widths on existing freeways to increase the number of mainlanes and capacity. The report analyzed years of operational and safety data for multiple freeways where reductions in shoulder and/or lane widths were utilized to increase capacity and reduce congestion. In addition, several of the projects studied utilized reduced lane widths and shoulder reductions to add capacity between major interchanges. The report's findings determined that in study sections were inside shoulders were reduced to improve capacity (and reduce congestion) the overall safety either improved or was unchanged. The report notes that generally improved safety operations were not just short term benefits but appear to be permanent. Limited study data suggests that no increases in the severity of accidents were taking place in the study sections. In addition, the study indicates that 11-foot travel lanes do not create safety problems. The report's Implementation Statement is included below. "The study findings indicate that inside shoulder reductions (all but 2 feet) are a simple and safe method of reducing congestion on existing freeways. The safety benefits of removing inside shoulders suggest that spot improvement projects should be undertaken when bottlenecks exist and analysis suggests that congestion can be reduced. Initial evaluation also suggests that median transit ways involving inside shoulder removals are a simple and safe method of improving person movement in Texas freeway corridors experiencing congestion and for which right-of-way acquisition is not practical." As previously discussed, existing IH 45 provides 10-lanes (5-lanes each direction) between the existing S.M. Wright and IH 30 interchanges. Providing four 11-foot lanes in each direction with reduced, 2-foot inside shoulders from the proposed C.F. Hawn Freeway (US 175) interchange up to the existing 10-lane section (5-lanes each direction) north of the existing S.M. Wright interchange effectively serves as a bottleneck relief for IH 45. The design exceptions proposed for IH 45 are consistent with the TTI report's findings and Implementation Statement. REPORT NO. FHWA/TX-09/0-4703-P2: A 2009 technical report by the Texas Transportation Institute titled the Roadway Safety Design Workbook analyzed the relationship between various highway geometric design components and crash frequency. The Roadway Safety Design Workbook uses accident modification factors for specific geometric parameters associated with a particular roadway. The overall expected crash rate is determined by multiplying all the accident modification factors along with the base crash rate. From this analysis, it was determined that from 2007 to 2010, IH 45 recorded fewer serious accidents than the baseline projections developed from TRSD methodologies (see Section 4, Table 8 for details). TRSD guidance was also used to analyze the impacts of various inside and outside shoulder widths along IH 45 for the proposed improvements. TRSD guidance allows for different accident modification factors for varying inside and outside shoulder widths. An analysis was performed to determine how variations in the shoulder widths would affect the overall expected crash rate. Two specific alternatives were considered, a 2-foot inside shoulder / 10-foot outside shoulder, and a 4- foot inside shoulder / 8-foot outside shoulder. Both alternatives assumed 11-foot wide lanes and continuous traffic barriers along both the inside and outside shoulders. All other variables were not included as their accident modification factors would remain constant between both shoulder width Page 12 of 13

S.M. Wright Project alternatives. The results are listed in the Table 12 below. Table 12 TRSD Analysis of Proposed Shoulder Widths Inside Shoulder Width Outside Shoulder Width Inside Shoulder Width AMF Outside Shoulder Width AMF Combined Shoulder AMF 2 10 1.11 1.00 1.11 4 8 1.08 1.01 1.09 The TRSD analysis results show that a 4-foot inside shoulder / 8-foot outside shoulder would provide a slight improvement (approximately 1%) in expected crashes as opposed to a 2-foot inside shoulder / 10-foot outside shoulder. However, either condition would require a traffic rail adjacent to both outside shoulders the entire length of the design exception due to existing structures or the proximity of parallel frontage roads. Since the difference is negligible, a 2-foot inside shoulder and a full 10-foot outside shoulder were utilized for the proposed improvements on IH 45 to maximize the available refuge between the face of the outside barrier and the outer lane line. Future Improvements The proposed design exceptions associated with IH 45 should be considered interim, although they could be in place for several years. Ultimate improvements to IH 45 that meet minimum design values are not included in the current MTP, "Mobility 2035" due to financial constraints. As previously discussed above, the Mobility 2035 plan is the long range planning document for the Dallas-Fort Worth area. The development of Mobility 2035 required a re-evaluation of expected funding sources that were included in previous MTPs for the Dallas-Fort Worth area. This re-evaluation resulted in the removal of nearly $45 billion of funding from the plan which required the prioritization of needed projects and the deferral of many key controlledaccess roadway projects necessary for the management of existing and future congestion. IH 45 was one of the corridors that was deferred from the previous MTP, "Mobility 2030". As noted in the current plan, "For the freeway and tollway corridors deferred from Mobility 2035, the reality that they cannot be incorporated into the plan based on projected financial constraints should not diminish the fact that significant congestion will increase in these corridors over time and large-scale improvements will be required at some point in the future These projects are still warranted and needed but must be deferred until additional regional funding can be identified." IH 45 from IH 30 to IH 20 is shown in the Mobility 2035 plan as a deferred project and is noted as a "corridor for future evaluation". IH 45 will be included in future MTP updates as funding is identified. Those future studies would reconstruct IH 45 to minimum values and would remove the design exceptions proposed by the S.M. Wright Project. Page 13 of 13

APPENDIX B SM Wright Phase Tech Memo

Halff Associates, Inc. 1201 North Bowser Road Richardson, Texas 75081 (214) 346-6200 Fax (214) 739-0095 MEMORANDUM FROM: Halff Associates, Inc. TO: TxDOT, FHWA Chad Gardiner, PE SUBJECT: Request for Design Exceptions on IH 45 and Revisions to the Proposed IH 45 Ramping SM Wright Project, TxDOT Dallas District DATE: June 25, 2013 The purpose of this memorandum is to summarize recent design changes to the SM Wright Project design schematic and any potential impacts these revisions may have to the request for Design Exceptions along IH 45. The SM Wright Project is located in Dallas, TX and the proposed improvements would include: Removing the accident prone, 90 degree curve in the US 175 alignment at the SH 310 interchange. This would be accomplished by realigning US 175 (CF Hawn Freeway) westerly to overpass SH 310/SM Wright Parkway and Lamar Street and constructing a new interchange with IH 45. Widening the existing IH 45 main lanes to the inside upstream of the proposed US 175 two-lane DC ramp junctions to allow for an additional transition lane (each direction) that would serve traffic between the proposed US 175 interchange and the existing IH 45 ten-lane section north of the existing US 175 (SM Wright) interchange. Removing the existing IH 45 half diamond ramps south of Pennsylvania Avenue would also be required due to ramp spacing constraints. Converting existing US 175 north of the SH 310 interchange from an existing six-lane freeway with frontage roads to a low speed, signalized six-lane urban arterial. SUMMARY OF PREVIOUS COORDINATION The design schematic, IH 45 IAJR, and request for Design Exceptions (DE) were submitted and reviewed by TxDOT and FHWA in the first half of 2012. On July 9, 2012, FHWA stated that the project was satisfactory to proceed and granted preliminary approval of these documents. RECENT IH 45 RAMP REVISIONS TO THE DESIGN SCHEMATIC A Public Hearing for the SM Wright project was held on January 31, 2013. Draft design schematics were displayed at the public meeting. At the Public Hearing, citizens expressed concerns regarding the proposed elimination of the existing northbound exit ramp from IH 45 to Pennsylvania Avenue and Martin Luther King Jr. Boulevard. This ramp was eliminated due to spacing constraints with the proposed northbound direct connecting entrance ramp from US Page 1 of 3

Halff Associates, Inc. 1201 North Bowser Road Richardson, Texas 75081 (214) 346-6200 Fax (214) 739-0095 175 (CF Hawn Freeway). The proposed schematic provided access from northbound IH 45 to Lamar Street, Pennsylvania Avenue, and Martin Luther King Jr. Boulevard from a one-lane exit ramp located south of Lamar Street. Traffic travelling to Pennsylvania Avenue and Martin Luther King Jr. Boulevard would be required to pass through the Lamar Street intersection. Due to the concerns expressed at the January Public Hearing, revisions were made to the proposed entrance and exit ramps on IH 45 south of Lamar Street. These changes will be presented in detail to the public at a second Public Hearing scheduled for June 27, 2013 at the Park South YMCA, 2500 Romine Avenue, Dallas, TX 75215. The revisions include the following: Revising the proposed northbound one-lane exit ramp located south of Lamar Street to a two-lane exit ramp. The two-lane exit ramp would split into two one-lane ramps approximately 1000 north of the main lane exit gore. One ramp drops down to provide access to Lamar Street. The other ramp overpasses Lamar Street and merges with the northbound frontage road north of Lamar Street. A third lane would be added to the frontage road downstream of the ramp gore. Adding a southbound entrance ramp north of Lamar Street. This entrance ramp would diverge from the southbound frontage road north of Lamar Street and overpass Lamar Street. The one-lane entrance ramp would merge with the proposed one-lane entrance located south of Lamar Street by utilizing a 50:1 taper. Downstream of the ramp merge, the one-lane entrance ramp would merge with the southbound main lanes. POTENTIAL IMPACTS TO THE APPROVED IH 45 DESIGN EXCEPTIONS The previous Request for Design Exceptions along IH 45 included the minimum values below. Minimum 12-foot wide lane widths could not be obtained on IH 45. Minimum 11-foot wide lane widths would be provided along IH 45. A Minimum 10-foot wide inside shoulder width could not be obtained on IH 45. A minimum 2-wide inside shoulder would be provided along IH 45. The schematic as shown at the January 2013 Public Hearing would maintain these minimum values for 1.2 miles along the northbound main lanes and 1.5 miles along the southbound main lanes. The recent ramp revisions would maintain these minimum values for 1.3 miles along the northbound main lanes and 1.5 miles along the southbound main lanes. Table 1 below provides a more detailed comparison of the design exception limits as shown on the January 2013 Public Hearing schematic (previously approved design exception request) and the currently revised schematic. Page 2 of 3

Halff Associates, Inc. 1201 North Bowser Road Richardson, Texas 75081 (214) 346-6200 Fax (214) 739-0095 Table 1 Comparison of Design Exception Limits Schematic Version January 13 Public Hearing Schematic Current Revised Schematic Northbound Southbound From To From To 611 N. of Lamar (sta. 505+71) 215 N. of Lamar (sta. 501+75) SM Wright ramp (sta. 568+38) SM Wright ramp (sta. 568+38) 579 S. of Lamar (sta. 493+81) 875 S. of Lamar (sta. 490+85) SM Wright ramp (sta. 571+16) SM Wright ramp (sta. 571+16) As the table indicates, the northern limit of the design exception in both the northbound and southbound directions did not change. The revisions to the design exception limits occur at the southern limit. No additional design exceptions would be required for the recent ramp revisions. CONCLUSIONS REGARDING THE REQUEST FOR DESIGN EXCEPTIONS Based on the limits in Table 1, the recent ramp revisions increase the length of the northbound DE by approximately 396 feet and the southbound DE by approximately 296 feet. The analysis and conclusions presented in the 2012 IH 45 request for DEs remain valid. Page 3 of 3

APPENDIX C SM Wright Phase I Design Exception Approval Memo