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Boundary Channel Drive at I-395 Interchange

Improved Safety and Operations for Drivers, Pedestrians, and Cyclists

Aerial view of the new roundabouts and I-395 looking northeast into Washington D.C. Photo courtesy Shirley Contracting Company, LLC.

Aerial view of the new roundabouts and I-395 looking northeast into Washington D.C. Photo courtesy Shirley Contracting Company, LLC.

New roundabout design with the shared use path connection to the Mount Vernon Trail in the background. Photo courtesy Shirley Contracting Company, LLC.

New roundabout design with the shared use path connection to the Mount Vernon Trail in the background. Photo courtesy Shirley Contracting Company, LLC.

Prior to improvements, the interchange remained generally unchanged since its construction with the Pentagon Reservation prior to World War II in the 1940s. The Pentagon is pictured in the background. Photo courtesy Shirley Contracting Company, LLC.

Prior to improvements, the interchange remained generally unchanged since its construction with the Pentagon Reservation prior to World War II in the 1940s. The Pentagon is pictured in the background. Photo courtesy Shirley Contracting Company, LLC.

The existing interchange ramps were replaced by two roundabouts, improving operations and safety. Photo courtesy of Shirley Contracting Company, LLC.

The existing interchange ramps were replaced by two roundabouts, improving operations and safety. Photo courtesy of Shirley Contracting Company, LLC.

The new roundabouts have improved access to recreational activities. The Long Bridge Aquatics and Fitness Center is pictured in the background. Photo courtesy Shirley Contracting Company, LLC.

The new roundabouts have improved access to recreational activities. The Long Bridge Aquatics and Fitness Center is pictured in the background. Photo courtesy Shirley Contracting Company, LLC.

The project improved paths for pedestrians and bicyclists with enhanced pedestrian safety signing and pavement markings.

The project improved paths for pedestrians and bicyclists with enhanced pedestrian safety signing and pavement markings.

Client
Shirley Contracting Company, LLC
Owner
Virginia Department of Transportation
Location
Arlington, VA
Markets
Transportation
Cost
$14.8 million
Completed
2024
Region
Mid-Atlantic

In 2021, as part of the Shirley-Dewberry design-build team, our firm was awarded the contract to complete improvements to Boundary Channel Drive at the I-395 Interchange in Arlington County, Virginia. This operational and safety improvement project consisted of reconfiguring the existing full cloverleaf interchange to a partial cloverleaf interchange by eliminating the back-to-back loop ramps west of I-395. Boundary Channel Drive was reduced from four to two lanes and the existing crossroad ramp terminals on each side of I-395 were converted to roundabouts. The project also included an auxiliary lane extension on I-395 and construction of a westbound shared use path, an eastbound sidewalk, and a shared use path connection from the interchange pedestrian facilities to the Mount Vernon Trail. Associated improvements consisted of complete pavement reconstruction, storm sewer system modifications, interchange lighting additions, landscaping, Rectangular Rapid Flashing Beacons (RRFB) installations, overhead sign modifications, ramp meter signal modifications, the addition of a fiber duct bank for the county, and waterline relocations.

The purpose and need of the project was to improve operations, increase connectivity, and address pedestrian and bicyclist safety concerns. Issues surrounding these focus areas had increased over time given that the interchange remained generally unchanged since its construction with the Pentagon Reservation prior to World War II in the 1940s. The reconfiguration emphasizes safety improvements for drivers, pedestrians, and bicyclists by incorporating pedestrian facilities and traffic calming measures, such as the roundabouts and RRFB at shared-use path crossings. The changes have also provided easier access to regional community, social, and economic facilities, national parks and monuments, and recreational amenities in the area.

This project required a significant number of stakeholders and coordination with each. Stakeholders included the Virginia Department of Transportation, Arlington County, Washington Headquarters Services (WHS), the Department of Defense, the Washington Metropolitan Area Transit Authority, and the National Park Service. It was also important to maintain uninterrupted access to the Pentagon Reservation throughout construction.

In addition to the roadway and interchange design, our firm provided all engineering design and environmental permitting services, including roundabout design and operational analysis; hydraulic design and stormwater management analysis; traffic engineering, including temporary traffic control, transportation management, signing and marking, roadway, and roundabout lighting; and interchange and roundabout landscaping design. Our survey and environmental team completed a detailed tree location and species survey to identify and establish tree protection areas. Our landscape architects designed a plan to replace the impacted landscaping and proposed new elements that were consistent with the surrounding area and native species.

2

new roundabouts

450

linear feet of new auxiliary lane along I-395

33

ADA curb ramps and refuge islands

2,300

linear feet of shared use path

Awards

  • 2025 Virginia Engineering Excellence Merit Award

    American Council of Engineering Companies (ACEC)

  • 2025 Engineering Honorable Mention Award

    Virginia Transportation Construction Alliance (VTCA)

  • 2025 Mid-Atlantic Nominee for National Project of the Year

    American Society of Highway Engineers (ASHE)

  • 2025 Infrastructure Award

    Heavy Construction Contractors Association

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