2 Transportation Improvement Alternatives

Transcription

1 Transportation Improvement Alternatives Transportation Improvement Alternatives This section documents the development of alternatives for transportation improvements in support of the redevelopment of the St. Elizabeths for the DHS Headquarters, including improvements to Martin Luther King, Jr. Avenue (MLK Avenue), Firth Sterling Avenue, and the I-95/Malcolm X Interchange as well as constructing a road from Firth Sterling Avenue to Malcolm X Avenue that will provide access to the St. Elizabeths West Campus. The Transportation Improvement Alternatives section describes the process used to develop the alternatives evaluated within this volume of the Final EIS. The National Environmental Policy Act (NEPA) requires the development and evaluation of all reasonable alternatives as part of the environmental impact statement process for a major transportation project. Alternatives are evaluated in terms of engineering feasibility, sensitivity to the environment, and ability to satisfy the project needs. The alternatives development process included a comprehensive public and agency involvement program. The affected public and regulatory agencies were involved in the development of preliminary corridors and the identification of alternatives to study in the EIS..A Alternatives Development Process To create alternatives for transportation improvements, the General Services Administration (GSA), in cooperation with the Federal Highway Administration (FHWA) and the DC Department of Transportation (DCDOT), assembled a project team of urban planners, architects, architectural historians, environmental scientists, engineers, and financial analysts. The project team identified and studied existing resources and development considerations before developing alternatives. The project team s activities included: Identifying the historic and current significant views both to and from the study area Identifying natural resources such as forested areas, streams, and protected species Identifying engineering constraints such as steep slopes and unstable soils Analyzing traffic impacts to local and regional roadways Final EIS Volume II Transportation Improvements -

2 Transportation Improvement Alternatives Analyzing availability of public transportation and other transportation management alternatives such as car-pooling, adjusted work schedules, and telecommuting As GSA developed the Transportation Improvement Alternatives, it worked to find a balance between project needs and the individual resources that could be affected by the project. Throughout the study process and the development of alternatives, GSA asked for input from public and government agencies through scoping, stakeholder meetings, public meetings with Advisory Neighborhood Commissions and the general public, and consulting parties meetings under the Section 06 process. Input from the public and government agencies is again requested on this Final EIS. 0.A. Resource Considerations As noted in the previous sections, research was conducted to identify issues and resources that needed to be considered in the development of Transportation Improvement Alternatives. Following is a summary of some of the key issues that were considered in the development of the individual Transportation Improvement Alternatives. 5.A..a St. Elizabeths Hospital East and West Campuses The St. Elizabeths Hospital is a National Historic Landmark (NHL). The NHL designation covers 8 contributing resources on the East and West Campuses including buildings, landscapes, vistas of the river and city, and the West Campus Cemetery. Since construction of an access road on the West Campus and widening of MLK Avenue would affect a NHL, Section 0(f) of the National Historic Preservation Act (NHPA) applies to the project. Section 0 requires the head of the responsible federal agency to undertake such planning and actions as may be necessary to minimize harm to a NHL. The goal of preservation under Section 0 is to protect the entire NHL. However, based on the assessments undertaken, it was determined that certain key character-defining features should be preserved to the extent possible under all of the Transportation Improvement Alternatives. These features include: The West Campus wall along MLK Avenue - Final EIS Volume II Transportation Improvements

3 Transportation Improvement Alternatives The entrance road into the West Campus from Gate to the Center Building and the associated trees along the roadway The historic internal roadway network In developing alternatives, special consideration was given to protecting the West Campus Cemetery on the slope northwest of the Center Building. All of the Transportation Improvement Alternatives were designed to not only avoid direct encroachment on the cemetery, but also to protect the landscape surrounding the cemetery. The cemetery will be placed outside of security fencing to allow for controlled public access. 9.A..b Natural Resources 0 5 The transportation study area contains natural resources including wetlands, streams, and large contiguous forested areas. The project team assessed the condition of natural resources and minimized construction in areas with mature forested areas, wetlands, and streams. A bald eagle s nest is located on Shepherd Parkway. A 660-foot radius around the nest was identified and protected with only limited encroachment at the outer edge from a perimeter fence that follows the site topography. 6.A..c Access/Roadway Network The regional roadway network and access to St. Elizabeths were studied to assist in determining the maximum number of employees that could access the site; the availability of mass transit and other intermodal solutions to access; and the need for additional vehicular access points to the site. Regional vehicular access to St. Elizabeths is provided via I-95, I-95, and I-95 from the north and south, and Route 50 and I-66 from the east and the west. Regional traffic in the vicinity of St. Elizabeths is congested at times during the rush hour periods in some locations. The local roadway network provides access from Suitland Parkway and South Capitol Street. The campus has direct access on MLK Avenue via two gates. A third gate to the campus is located below the grade level of MLK Avenue and provides a tunnel connection directly to the East Campus. Final EIS Volume II Transportation Improvements -

4 Transportation Improvement Alternatives The Anacostia Metrorail Station is approximately 0.56 miles from the West Campus Gate, approximately 0.99 miles from the West Campus Gate, and 0.7 miles from the West Campus Gate tunnel. The Congress Heights Metrorail Station is approximately.7 miles from the West Campus Gate, approximately.0 mile from the West Campus Gate, and 0.7 miles from the West Campus Gate. In addition, a number of bus routes located on MLK Avenue provide accessibility to local destinations including the Anacostia Metrorail Station. The area lacks bicycle routes and paths. 8.A..d Views Significant views toward I-95, Shepherd Parkway, and the St. Elizabeths West Campus can be found in nearby locations such as the Washington Navy Yard, Hains Point at East Potomac Park, and vehicular approaches to the campus. In addition, the views of the wooded ridge (or topographic bowl) on which St. Elizabeths stands, but not included in the hospital s landmark designation, are considered by metropolitan planning agencies to be important elements of the Washington, DC viewshed in the Federal Elements of the Comprehensive Plan for the National Capital. 6.A..e Shepherd Parkway The Shepherd Parkway, extending south of the St. Elizabeths West Campus, along the eastern side of I-95, is under the jurisdiction of the National Park Service. The Shepherd Parkway is not a road, but is part of the Fort Circle Parks, a series of parklands which contain Civil War earthworks. The Shepherd Parkway is land that was set-aside by the United States to build a road to be called Fort Circle Drive. The road was never constructed, and the Fort Circle Parks were divided between three Washington, D.C. area National Park Service units George Washington Memorial Parkway, Rock Creek Park, and National Capital Parks-East. The Shepherd Parkway is managed by the National Park Service National Capital Parks-East and is noted for containing mature native hardwood forest and unique geologic features. Within the transportation study area, Shepherd Parkway contains steep slopes (greater than 5%) and does not have recreational amenities or a designated entrance. There is substantial dumping of miscellaneous waste within the Shepherd Parkway. - Final EIS Volume II Transportation Improvements

5 Transportation Improvement Alternatives.A..f Bolling Air Force Base Historic District The first Bolling Air Field was established north of the current Air Force Base in what is now the Naval Air Station. Construction on the present Bolling Air Force Base began in 9. Transfer of personnel from the old air field was completed by 90. The General Headquarters of the Army Air Forces moved into the facility in 9. When the U.S. Air Force was established in 97, Bolling became Headquarters Command USAF. The National Register eligible historic district includes 75 buildings constructed between 9 and 95, including officers quarters, barracks, hangars, and service buildings. The Bolling Air Force Base Historic District is shown on Figure -. 0.A..g Congress Heights Firehouse; Congress Heights Historic District The Congress Heights Firehouse at 0 MLK Avenue, SE, has been a neighborhood landmark since its construction in 90. It was Washington s largest firehouse at the time of its construction. The red brick Italianate design incorporated operational and construction innovations such as an observation tower and a steel truss roof. It was listed in the D.C. Historic Inventory on July, 00. Congress Heights, the neighborhood southwest of St. Elizabeths Hospital and developed in the early twentieth century, was surveyed in and determined to be eligible for listing in the National Register. The Congress Heights Firehouse and the Congress Heights Historic District are shown on Figure -. 9.A. Alternatives Considered But Eliminated From Detailed Study In general, the goal of the project team was to develop possible routes or preliminary alternatives that would meet engineering design criteria for safety and satisfy the project needs while avoiding as many sensitive features as possible. When it is impossible to avoid impacting a feature, the study team attempted to minimize the impact as much as possible. During the preliminary alternatives development, the broadest feasible spectrum of roadway improvements was examined. The goal was to narrow the field of preliminary alternatives and only study alternatives that meet the project needs. GSA studied several alternatives and either retained or dismissed each based on whether or not they were feasible or prudent from an engineering and/or traffic standpoint. Below is a summary of the dismissed alternatives. GSA retained for detailed study the Malcolm X/I-95 interchange and construction of a new access Final EIS Volume II Transportation Improvements -5

6 Transportation Improvement Alternatives road from Malcolm X Avenue to the West Campus even though it would impact a sensitive feature, the Shepherd Parkway as it was the most feasible and prudent alternative from an engineering and traffic standpoint. Access to South Capitol Street South Capitol Street is located adjacent to and west of I-95. Alternatives to create a direct access from South Capitol Street to the St. Elizabeths West Campus were studied. South Capitol Street and the St. Elizabeths West Campus are separated by I-95; therefore it would be necessary to provide a fly-over over I-95 or a tunnel under I- 95 to create a direct access point. A fly-over over I-95 would require at least 5 feet of vertical clearance. Ramping up the road from South Capitol Street to this height would require unreasonable grades because there is not enough horizontal distance between South Capitol and I-95. Tunneling under I-95 would present similar engineering issues. Because there is insufficient space to allow for a reasonable grade for a flyover or a tunnel, direct access from South Capitol Street to the St. Elizabeths West Campus is not feasible. Direct Access from I-95 This alternative would provide for direct access between the St. Elizabeths West Campus and I-95. A design waiver from FHWA would be required for a new access point on I-95 due to the close proximity of the I-95/Suitland Parkway interchange to the north and the I-95/Malcolm X interchange to the south. The addition of a new interchange on I-95 to the St. Elizabeths campus between the existing interchanges would create weave problems on I-95. In addition, FHWA s policy for new interstate access points states that new or revised access points to the existing Interstate System should meet the following requirements: The proposed access connects to a public road only and will provide for all traffic movements This requirement cannot be met as a new interchange on I-95 would only be for employees and visitors to the St. Elizabeths West Campus, not a public road, and all traffic movements could not be accommodated. Land and buildings from the Anacostia Naval Annex would need to be acquired to construct a fly-over access ramp from southbound I- 95 to the campus. The Naval Annex does not have land available to relocate buildings that would be demolished under this alternative. Suitland Parkway (via a connection to the St. Elizabeths East Campus) Only percent of the traffic accessing the consolidated DHS Headquarters at St. Elizabeths is expected to arrive via westbound Suitland Parkway. Therefore, creating a direct connection from the Parkway for all DHS traffic coming to St. Elizabeths would not meet the project need. -6 Final EIS Volume II Transportation Improvements

7 Transportation Improvement Alternatives Access to St. Elizabeths East Campus from Suitland Parkway may be feasible via a long and relatively steep fly-over ramp from the parkway to the St. Elizabeths East Campus. Both the Suitland Parkway and the East Campus are historic resources. Access between the East Campus and the West Campus would need to be provided via the existing at-grade gates on Martin Luther King, Jr. Avenue or via a tunnel connection to the East Campus (similar to the existing tunnel connection at the West Campus Gate ). Putting West Campus traffic back on Martin Luther King, Jr. Avenue would not alleviate traffic congestion at the existing Martin Luther King, Jr. gates. Providing a vehicular tunnel connection would create security problems for the DHS Headquarters. Also, this alternative would not provide a connection to the western side of the campus close to planned parking locations, requiring the widening of roadways within the St. Elizabeths West Campus to allow two-way traffic, including delivery trucks, to traverse the site. This alternative would also require acquiring land and could potentially include demolition of historic buildings on the East Campus. Alternate access from Suitland Parkway to St. Elizabeths East Campus will likely be studied as part of future East Campus redevelopment plans. Access via Martin Luther King Jr. Avenue (new gate) Under this alternative, all traffic coming to the DHS Headquarters at St. Elizabeths would arrive via MLK Avenue. An additional gate into the St. Elizabeths West Campus from MLK Avenue would be added under this alternative. This alternative would have major impacts on local traffic as all employees, visitors, and deliveries coming to the DHS Headquarters would need to access the campus from MLK Avenue. A new access point on MLK Avenue would not provide access to the western edge of the campus close to potential parking locations without widening the historic roadways within the St. Elizabeths NHL to allow two-way traffic to traverse the site. The limited distance between adjacent gates/intersections would not allow for efficient traffic operations. Access via Firth Sterling Avenue Under this alternative, Firth Sterling Avenue would be widened to accommodate 70 percent of the vehicles coming to the St. Elizabeths West Campus, and a new access road would be constructed from Firth Sterling Avenue into the West Campus. The remaining 0 percent of vehicles accessing the DHS Headquarters would arrive via MLK Avenue. This alternative would not meet the project s purpose and need because it would not provide adequate capacity to handle the traffic generated by the DHS Headquarters. Traffic from 70 percent of the vehicles accessing the West Campus via Firth Sterling Avenue would create queuing problems on Firth Sterling Avenue from vehicles waiting to clear security checkpoints on the campus. In addition, without additional access points, the volume of traffic Final EIS Volume II Transportation Improvements -7

8 Transportation Improvement Alternatives created by the DHS Headquarters would cause intersections at Firth Sterling Avenue to fail. In order to provide adequate levels of service, the I-95 and Suitland Parkway interchange with Howard Road and Firth Sterling would need to be reconstructed which could impact the Anacostia Metrorail station and the Suitland Parkway, which is itself a Section (f) resource. In addition, Firth Sterling would need to be widened resulting in the acquisition of businesses including a Verizon facility and acquisition of portions of the Barry Farm public housing complex This alternative has been studied as Alternative I-0 in this volume of the Final EIS. This alternative is included to provide an assessment of impacts that would occur if FHWA does not approve modifications to the Malcolm X/I-95 interchange eliminating the potential to construct the access road from Malcolm X into the St. Elizabeths West Campus..B No Action Alternative Under the No Action Alternative, the DHS Headquarters would not be consolidated at St. Elizabeths and no additional traffic would be generated. Under the No Action Alternative, no land acquisition would occur. Although the No Action Alternative would not meet the purpose of and need for the project, NEPA requires GSA to consider the No Action Alternative because it provides a baseline for evaluating the environmental impacts of the alternatives for the proposed action. The No Action Alternative also serves as a basis for determining whether the public benefits of the proposed transportation improvements outweigh the probable environmental impacts. It should be noted that the No Action Alternative studied in Volume I of this EIS assesses impacts that would occur if redevelopment of St. Elizabeths for the DHS Headquarters consolidation is not undertaken. In the interest of minimizing redundancy between the two volumes, this analysis has not been repeated in Volume II..C Transportation Improvement Alternatives Four Interchange/Access Road Alternatives along with a no-build alternative (Alternative I-0) have been considered in detail in this EIS. Included in each alternative is the reconfiguration of the intersection of Firth Sterling Avenue/Stevens and Barry Roads to tie into a new access road that would enter the St. Elizabeths West Campus at the northwest perimeter to a gated entrance -8 Final EIS Volume II Transportation Improvements

9 Transportation Improvement Alternatives to the south of the West Campus Cemetery. In Alternatives I- through I-, the access road would then continue south to Shepherd Parkway before tying into a reconstructed interchange at Malcolm X Avenue and I-95. Each of these alternatives are compatible with any of the St. Elizabeths Campus Redevelopment Alternatives, shown in Volume I of this Final EIS. Two alternatives were considered for improvements to MLK Avenue, which fronts the eastern boundary of the St. Elizabeths West Campus, separating it from the East Campus to provide turn lanes for vehicles entering the St. Elizabeths West Campus. The following alternatives for improvements to MLK Avenue are compatible with any of the Interchange/Access Road Alternatives described in this section. Improvements to Firth Sterling Avenue and MLK Avenue and construction of the proposed access road would be funded by GSA. It is expected that funding for the Malcolm X Avenue/I- 95 interchange improvements would come from other Federal sources.c. Interchange/Access Road Alternatives The GSA project team worked with DDOT and FHWA to develop alternatives to improve the Malcolm X/I-95 interchange and construct a new access road from Malcolm X Avenue to Firth Sterling Avenue. At DDOT s request, GSA assessed alternatives that would improve the traffic situation not only for the DHS Headquarters, but also improve existing deficiencies associated with the I-95/Malcolm X partial interchange, the South Capitol Street/Malcolm X interchange and the main Bolling Air Force Base access gate. The project team developed a total of interchange concepts. Of these alternatives four alternatives along with a no-build alternative (Alternative I-0) have been studied in detail in this EIS. Through consultation with DDOT and FHWA, the following seven alternatives were dismissed: Full cloverleaf A full cloverleaf interchange would extend onto the Bolling Air Force base and its newly constructed security screening area. Quarter cloverleaf plus elongated loop ramp This concept would replace the existing northbound loop on-ramp with an increased I-95 loop ramp and an elongated northbound loop off-ramp. This alternative would push the proposed St. Elizabeths access road east on Malcolm X Avenue and would require significant retaining walls. Also this concept would have greater impacts on the Shepherd Parkway. Final EIS Volume II Transportation Improvements -9

10 Transportation Improvement Alternatives Half cloverleaf with wide diamond ramp This concept would separate the St. Elizabeths West Campus site access from the I-95 interchange ramps. This alternative would have significant impacts to the Shepherd Parkway since the proposed access road would be located much further east. Also this alternative would require significant retaining wall heights. Half tight diamond with site access from ramp This concept would create an undesirable situation with two-way traffic accessing St. Elizabeths mixing with one-way interstate traffic. Also the access road would require a traffic signal. A traffic signal should not be provided in the middle of an interstate on-ramp when traffic should be accelerating, not stopping. Half tight diamond with five leg intersection This alternative would require confusing and double left-turns at a five-leg intersection. Traffic demands from Bolling Air Force Base would require a double left turn lane from eastbound Malcolm X Avenue onto the I-95 northbound on-ramp. Also a double left turn lane would be required for traffic to turn onto the campus. It would be unsafe to provide double left turns for both legs at this five leg intersection. Full tight diamond with five leg site access This alternative would eliminate the Malcolm X/South Capitol Street ramps and would provide full access to I-95. However, this alternative would still provide confusing left-turns at the five-leg intersection (see half tight diamond alternative above). Also preliminary traffic analyses indicate that this alternative would not operate with acceptable traffic levels due to the close spacing between the two traffic signals that would be required at the diamond ramps. Single point interchange with one-way service road This alternative would only allow one-way access to the St. Elizabeths West Campus from Malcolm X Avenue. This alternative would not meet the access needs of the campus. As noted previously four Interchange/Access Road Alternatives along with a no-build alternative (Alternative I-0) have been considered in detail in this EIS. Included in each alternative is the reconfiguration of the intersection of Firth Sterling Avenue/Stevens and Barry Roads to tie into a new access road that would enter the St. Elizabeths West Campus at the -0 Final EIS Volume II Transportation Improvements

11 Transportation Improvement Alternatives northwest perimeter to a gated entrance to the south of the West Campus Cemetery. Three alternatives were studied for reconstructing the Firth Sterling Avenue intersection with Stevens and Barry Road to accommodate the proposed access road. The GSA project team developed alternatives to improve Firth Sterling Avenue. A total of three concepts were developed. Through consultation with DDOT, the following two alternatives were dismissed: Five legged intersection Firth Sterling Avenue would be realigned. This alignment was not compatible with the streetcar tracks that DDOT is constructing alone Firth Sterling Avenue. Roundabout four out of the five streets at the Firth Sterling Avenue intersection would feed in and out of the roundabout, while one street would only feed out. This alignment was also not compatible with the streetcar track DDOT is constructing along Firth Sterling Avenue. As noted above, a new access road would be constructed from Firth Sterling Avenue into the St. Elizabeths West Campus. In Alternatives I- through I-, the access road would parallel I-95 through the West Campus, continuing south through the Shepherd Parkway before tying into Malcolm X Avenue near the reconstructed Malcolm X/I-95 interchange. The access road has been studied as a three-lane, two-way road that connects from Firth Sterling Avenue, SE to Malcolm X Avenue. The center lane would operate as a reversible lane that would accommodate inbound and outbound peak directional traffic flow. Additional lanes will be provided at the access road intersection with Malcolm X for turn lanes and at the new entrance gate for turn lanes and vehicle queuing for security processing. It should be noted that under Alternatives and 5, it may be feasible to reduce the access road to two lanes, thereby reducing impacts associated with the roadway. If the access road is reduced to two vehicle travel lanes then a bicycle-lane and sidewalk could be accommodated from Firth Sterling Avenue into the campus within the same currently proposed cross section. The bicycle-lane and sidewalk would help provide improved access from the west campus to the Anacostia Metrorail Station, the Naval Support Facility Anacostia (the Naval Annex), and the Barry Farm Redevelopment. The bicycle-lane and sidewalk would end at the campus limits and would still allow for reduced impacts through Shepherd Parkway to Malcolm X Avenue. GSA would continue to study Final EIS Volume II Transportation Improvements -

12 Transportation Improvement Alternatives reductions to the footprint of the roadway and the provision of a bicycle-lane and sidewalk during final design. To minimize impacts to vegetation and steep slopes within the St. Elizabeths West Campus and within the Shepherd Parkway, preliminary designs for Alternatives I-0 through I- incorporated the use of retaining walls. Table - provides an overview of retaining wall heights for each of the alternatives. The surface treatment for the retaining walls would be determined during final design and would be context sensitive. Table -. Approximate Retaining Wall Heights for Interchange/Access Road Alternatives Retaining Wall Heights On Shepherd Parkway south of Malcolm X Avenue On Shepherd Parkway north of Malcolm X Avenue On St. Elizabeths West Campus Alternative I-0 Alternative I- Alternative I- Alternative I- Alternative I- No new construction No new construction 8 ft to 9 ft 8 ft to 9 ft 8 ft to 9 ft 8 ft to 0 ft ft to 8 ft ft to 57 ft ft to 55 ft 5 ft to 7 ft ft to 5 ft ft to 5 ft ft to ft ft to ft ft to ft Retaining walls with similar heights are located in the District of Columbia along the Southeast- Southwest Freeway at the following locations (Parsons, 00): From 7 th Street, SW to 5 th Street, SW, an existing retaining wall varies from 7.0 to 0.5 feet in height. From th Street, SE to 5 th Street, SE, an existing retaining wall varies from.5 feet to.5 feet in height. Between 5 th Street SW and the D Street Tunnel, an existing retaining wall varies from 7.0 to.5 feet in height. Each of the Interchange/Access Road Alternatives described below are compatible with any of the St. Elizabeths Campus Redevelopment Alternatives, shown in Volume I of this Final EIS. - Final EIS Volume II Transportation Improvements

13 Transportation Improvement Alternatives C..a Interchange/Access Road Alternative I-0 Alternative I-0 has been studied in detail in this Final EIS to provide an assessment of impacts that would occur if FHWA does not approve modifications to the Malcolm X/I-95 interchange eliminating the potential to construct the access road from Malcolm X into the St. Elizabeths West Campus. Under Alternative I-0, 70 percent of the traffic accessing the DHS Headquarters would arrive via Firth Sterling Avenue. The intersection of Firth Sterling Avenue with Stevens and Barry Roads, located a block north of St. Elizabeths West Campus, would be re-configured to allow a functional and safe tie-in of a new access road to the West Campus. DDOT s plans for a new street car track will be under construction shortly, and so the intersection design assumes the street car track along Firth Sterling Avenue as an existing condition. However, the Frontage Road and Stevens Road legs of the intersection would be realigned. A slip ramp would be constructed for movements from eastbound Firth Sterling Avenue to the West Campus via the new access road. Barry Road would be a one-way road heading northbound. After crossing the northwest perimeter of St. Elizabeths West Campus, the access road would run parallel to I-95, before tying into a four-lane, two-way gated entrance to the south of the West Campus Cemetery. Retaining walls would border the access road on both sides. The height of the east retaining wall would vary between 8 and 0 ½ feet. The west retaining wall would be 8 ½ feet high. Alternative I-0 would not meet the project s purpose and needs because it would not provide adequate capacity to handle the traffic generated by the DHS Headquarters. Having 70 percent of the traffic accessing the DHS Headquarters arrive from Firth Sterling Avenue would create queuing problems on Firth Sterling Avenue from vehicles waiting to clear security checkpoints on the campus. In addition, without additional access points, the volume of traffic created by the DHS Headquarters would cause intersections at Firth Sterling Avenue to fail. Under Alternative I-0, land along Firth Sterling Avenue would need to be acquired to allow for widening of the roadway and reconfiguration of the intersection with Stevens Road and Barry Road. Alternative I-0, shown with Campus Redevelopment Alternative, is presented in Figure -. The Firth Sterling Avenue interchange improvements are shown in Figure -. Graphics of Alternative I-0 with Campus Redevelopment Alternatives and 5 can be found in Volume IV, Final EIS Volume II Transportation Improvements -

14 Transportation Improvement Alternatives Appendix F. Alternative I-0 has been studied with Campus Redevelopment Alternative in this Volume of the EIS to present the worst case impacts that would occur if interchange improvements are not made to the Malcolm X/I-95 interchange and the access road is not constructed from Malcolm X Avenue into the West Campus..C..b Interchange/Access Road Alternative I- Alternative I- includes all of the improvements described in Alternative I-0. Under this Alternative, south of the new gated entrance, the access road would continue to parallel I-95 and cross onto Shepherd Parkway. Approximately 750 feet north of Malcolm X Avenue, the road would turn east to intersect with Malcolm X Avenue. Between the new gated entrance and Malcolm X Avenue, the east retaining wall would rise from 5 to ½ feet, and the west retaining wall would vary from 8 to ½ feet. South of Malcolm X Avenue intersection, the east retaining wall would reach a maximum height of 8 ½ feet, and the west retaining wall would reach a maximum height of feet. Under Alternative I-, the Malcolm X/I-95 interchange would be modified, and the cloverleaf loop that connects northbound I-95 to westbound Malcolm X Avenue would be closed. A flyover on-ramp would diverge from the access road, approximately,800 feet north of Malcolm X Avenue, and would connect to southbound I-95. The ramp would cross over both northbound and southbound I-95 and merge with the latter south of Malcolm X Avenue. The total length of the flyover ramp and merge lane would be approximately,900 feet. The height of the flyover would have a minimum 5-foot clearance under the structure, and may reach 0- feet at the top. A new off-ramp would provide access to Malcolm X Avenue from northbound I-95. This ramp would begin approximately,000 feet south of Malcolm X Avenue, remaining close to the interstate before turning east approximately 750 feet south of Malcolm X Avenue. The southbound I-95 bridge span over Malcolm X Avenue would be widened in order to accommodate the flyover merging lane. Under Alternative I-, land along Firth Sterling Avenue would need to be acquired to allow for widening of the roadway and reconfiguration of the intersection with Stevens Road and Barry Road. In addition, land would be needed from the Shepherd Parkway to construct the interchange improvements and the proposed access road. - Final EIS Volume II Transportation Improvements

15 Transportation Improvement Alternatives Alternative I-, in conjunction with one of the Campus Redevelopment Alternatives presented in Volume I and one of the MLK Avenue Alternatives presented below, would meet the project s purpose and need. Alternative I-, shown with Campus Redevelopment Alternative, is presented in Figures - and -. Graphics of Alternative I- with Campus Redevelopment Alternatives and 5 can be found in Volume IV, Appendix F..C..c Interchange/Access Road Alternative I- Alternative I- is similar to Alternative I- with three exceptions: ) the retaining walls between the new gated entrance and Malcolm X Avenue would be higher; ) additional construction would take place in association with access to Malcolm X Avenue; and ) there would be no flyover ramp. Under Alternative I-, the east retaining walls would vary in height from 8 ½ to 8 ½ feet between the new access gate and Malcolm X Avenue. The west retaining walls would vary between ½ and ½ feet high in the same stretch. In Alternative I-, the access road would begin to turn east approximately,000 feet before it reaches Malcolm X Avenue to accommodate a loop road that would return access road traffic to I-95 north. Alternative I- also would close the cloverleaf loop that connects northbound I-95 to westbound Malcolm X Avenue. As in Alternative I-, a new off-ramp beginning approximately,000 feet south of Malcolm X Avenue would provide access to Malcolm X Avenue from northbound I-95. Alternative I- would include an on-ramp from westbound Malcolm X Avenue to I-95 north. Alternative I- would require the closing of the existing northbound South Capitol Street offramp to Malcolm X Avenue and the partial closing of the northbound South Capitol Street onramp from Malcolm X Avenue, allowing for only right turns from westbound Malcolm X Avenue. These ramp closures would allow for the critical elimination of the existing traffic signal at Malcolm X Avenue and the northbound South Capitol Street ramps. Final EIS Volume II Transportation Improvements -5

16 Transportation Improvement Alternatives Under Alternative I-, land along Firth Sterling Avenue would need to be acquired to allow for widening of the roadway and reconfiguration of the intersection with Stevens Road and Barry Road. In addition, land would be needed from the Shepherd Parkway to construct the interchange improvements and the proposed access road. Alternative I-, in conjunction with one of the Campus Redevelopment Alternatives presented in Volume I and one of the MLK Avenue Alternatives presented below, would meet the project s purpose and need. Alternative I- is presented in Figures -5 and -6. It is shown with Campus Redevelopment Alternative. Graphics of Alternative I- with Campus Redevelopment Alternatives and 5 can be found in Volume IV, Appendix F..C..d Interchange/Access Road Alternative I- Alternative I- is also similar to Alternative I- with two exceptions: ) the retaining walls between the new gated entrance and Malcolm X Avenue would be higher; and ) additional construction would take place in association with access to Malcolm X Avenue. Under Alternative I-, the east retaining walls would vary in height from 8 ½ to 0 ½ feet between the new access gate and Malcolm X Avenue. The west retaining walls would vary between and feet high in the same stretch. In Alternative I-, a median would be constructed along Malcolm X Avenue east and west of the intersection with the proposed access road. This new Malcolm X Avenue median would extend westward to the Bolling AFB entrance, requiring the lengthening of the two I-95 bridges over Malcolm X Avenue, as well as the widening of the Malcolm X Avenue bridge over South Capitol Street. New off- and on-ramps connecting southbound I-95 to and from Malcolm X Avenue are also planned in what would be the median between I-95 and South Capitol Street. These two diamond ramps would provide direct access between I-95 southbound and Malcolm X Avenue, thereby permitting the elimination of the following ramps: -6 Final EIS Volume II Transportation Improvements

17 Transportation Improvement Alternatives Partial closing of the southbound South Capitol Street off- and on-ramps to and from Malcolm X Avenue. Only the right turn into and out of the Bolling AFB entrance would be maintained along these two ramps. The existing South Capitol Street northbound off- and on-ramps to and from Malcolm X Avenue would be closed. This three-lane ramp would replace existing access to Malcolm X Avenue from southbound I-95. As in Alternatives I- and I-, Alternative I- would close the cloverleaf loop that connects northbound I-95 to westbound Malcolm X. Under Alternative I-, land along Firth Sterling Avenue would need to be acquired to allow for widening of the roadway and reconfiguration of the intersection with Stevens Road and Barry Road. In addition, land would be needed from the Shepherd Parkway to construct the interchange improvements and the proposed access road. Alternative I-, in conjunction with one of the Campus Redevelopment Alternatives presented in Volume I and one of the MLK Avenue Alternatives presented below, would meet the project s purpose and need. Alternative I- is presented in Figures -7 and -8 and is shown with Campus Redevelopment Alternative. Graphics of Alternative I- shown with Campus Redevelopment Alternatives and 5 can be found in Volume IV, Appendix F..C..e Interchange/Access Road Alternative I- Plans for this alternative are similar to the other alternatives. Differences exist in the height of the retaining walls in the northern portion of Shepherd Parkway and in the connection of Malcolm X Avenue with north-south traffic arteries. Under Alternative I-, the east retaining walls would vary from 5 to 8 feet tall between the new gated entrance and Malcolm X Avenue. The west retaining walls would vary between 7 ½ and ½ feet high in the same stretch. The access road would intersect Malcolm X Avenue approximately 50 feet farther east in Alternative I- than in the other alternatives. A new single point urban interchange at I-95 and Malcolm X Avenue would also require a new signalized intersection between Malcolm X Avenue and the ramps to/from I-95. The on- and Final EIS Volume II Transportation Improvements -7

18 Transportation Improvement Alternatives off-ramps connecting Malcolm X Avenue to northbound I-95 would require the closing of the two existing cloverleaf loops. The on-ramp from Malcolm X Avenue would enter northbound I-95 approximately,600 feet north of Malcolm X Avenue. The off-ramp connecting I-95 northbound to Malcolm X Avenue would begin approximately,800 feet south of Malcolm X Avenue. The proposed southbound I-95 ramps to and from Malcolm X Avenue would require the closing of the existing off-ramp from southbound I-95 to South Capitol Street, as well as the closing of the two existing northbound South Capitol Street ramps to and from Malcolm X Avenue. As in Alternative I-, the southbound South Capitol Street ramps to and from Malcolm X would be partially closed, allowing only right turns into and out of the Bolling AFB entrance. Under Alternative I-, land along Firth Sterling Avenue would need to be acquired to allow for widening of the roadway and reconfiguration of the intersection with Stevens Road and Barry Road. In addition, land would be needed from the Shepherd Parkway to construct the interchange improvements and the proposed access road. Alternative I-, in conjunction with one of the Campus Redevelopment Alternatives presented in Volume I and one of the MLK Avenue Alternatives presented below, would meet the project s purpose and need. Alternative I- is presented in Figures -9 and -0 with Campus Redevelopment Alternative. Graphics of Alternative I- with Campus Redevelopment Alternatives and 5 can be found in Volume IV, Appendix F..C. MLK Avenue Alternatives Two alternatives were considered for improvements to MLK Avenue, which fronts the eastern boundary of the St. Elizabeths West Campus, separating it from the East Campus. The following alternatives for improvements to MLK Avenue are compatible with any of the Interchange/Access Road Alternatives described above. Improvements to MLK Avenue would be funded by GSA -8 Final EIS Volume II Transportation Improvements

19 Transportation Improvement Alternatives C..a MLK Avenue Alternative MLK Avenue is currently comprised of four 0-foot wide lanes, with 5-foot wide sidewalks. Under MLK Avenue Alternative, MLK Avenue would be widened approximately 5 to 7 feet to the east from Pomeroy Road to south of Elm Street, a distance of 0 feet. An existing historic wall along the west side of MLK Avenue from Gate through Redwood Drive allows for widening only on the east side. Widening to the east side of MLK Avenue would require the use of land from the St. Elizabeths East Campus. New sidewalks would be also be constructed along the east side of MLK Avenue and would be separated from the roadway by greenspace. Both MLK Avenue alternatives would examine the possibility of increasing sidewalks on the East Campus to 6 to 8 feet as recommended in the Great Streets Framework Plan. Final design would need to be coordinated with DDOT and the Unified Communications Center as widening MLK Avenue would impact its existing security berm. Depending upon the width of the sidewalk, the total widening of the road plus sidewalks would be 0-feet to -feet. Under MLK Avenue Alternative, the 0-foot lanes in each direction would be widened to an -foot through lane and a -foot outside through/right turn shared lane. Ten-foot wide left turn lanes are proposed at Gates and (Cedar Street and Pine Street), also in both the northbound and southbound directions. The proposed left turn lanes would include northbound left turn storage length of 95 feet at Gate and 60 feet at Gate. The southbound left turn storage would be 0 feet at Gate and 95 feet at Gate. A 0-foot long painted median between left turn storage areas is proposed. New traffic signals are proposed at West Campus Gates and. In conjunction with any of the Campus Redevelopment Alternatives and one of the Interchange Alternatives, MLK Avenue Alternative would meet the project s needs. MLK Avenue Alternative is presented in Figure -..C..b MLK Avenue Alternative Under MLK Avenue Alternative, MLK Avenue would be widened approximately 5 to feet to the east from Pomeroy Road south of Elm Street, a distance of 00 feet. As with Alternative, the roadway could only be widened to the east side requiring land from the St. Elizabeths East Campus. Also, as in Alternative, new sidewalks would be also be constructed along the east Final EIS Volume II Transportation Improvements -9

20 Transportation Improvement Alternatives side of MLK Avenue and would be separated from the roadway by greenspace. Both MLK Avenue alternatives would examine the possibility of increasing sidewalks on the East Campus to 6 to 8 feet as recommended in the Great Streets Framework Plan. Final design would need to be coordinated with DDOT and the Unified Communications Center as widening MLK Avenue would impact its existing security berm. Depending upon the width of the sidewalk, the total widening of the road plus sidewalks would be 0-feet to 5-feet. Under MLK Avenue Alternative, the existing northbound and southbound lanes would be widened to an - to -foot outside through/right turn shared lane and an -foot through lane in each direction. Ten-foot wide left turn lanes are proposed at Gates and (Cedar Street and Pine Street), also in both the northbound and southbound directions. The proposed left turn lanes would include northbound left turn storage length of 95 feet at Gate and 60 feet at Gate. The southbound left turn storage would be 0 feet at Gate and 95 feet at Gate. A -foot long raised median is proposed along MLK Avenue between the left turn storage areas, with a -foot uninterrupted median at the intersection to allow for left turn lanes. New traffic signals are proposed at West Campus Gates and. Under MLK Avenue Alternative, 5-foot to 8-foot wide sidewalks would be constructed along the east side of MLK Avenue. In conjunction with one of the Campus Redevelopment Alternatives and one of the Intersection Alternatives, MLK Avenue Alternative would meet the purpose and needs of the project. MLK Avenue Alternative- is presented in Figure -..D Transportation Improvements - Preferred Alternatives In accordance with 0 CFR 50.(e), which requires that a preferred alternative be identified in this Final Environmental Impact Statement, the interchange preferred alternative is Alternative I- and the MLK Avenue widening preferred alternative is MLK Alternative. GSA's identification of these alternatives as preferred is based on coordination with, and is subject to, subsequent final determinations of the Federal Highway Administration and the DC Department of Transportation, agencies that are anticipated to base their approvals in part upon this Final Environmental Impact Statement. 9-0 Final EIS Volume II Transportation Improvements

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41 Transportation Improvement Alternatives Figure - Mapping of the St. Elizabeths East Campus is based on the latest available GIS data from the District of Columbia and does not illustrate recent development such as the DC Unified Communications Center. Final EIS Volume II Transportation Improvements -

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