The Virginia Department of Transportation (VDOT) is working on expanding its network of suburban Washington, D.C., managed express lanes, with eye toward having an 84-mile network in place by 2021.

According to a plan released March 31, VDOT will extend the I-95/395 Express Lanes, opened in 2014, approximately 8 miles to an interchange adjacent to the Pentagon. The project will complete the upgrade of a two-lane corridor originally built exclusively for buses and rush-hour high-occupancy vehicle (HOV) car pools into a three-lane facility open to all vehicles. Construction will include lane and ramp improvements, overhead signs and toll collection gantries, and noise walls.

As with the current Express Lanes, the corridor will be reversible to accommodate peak travel movements, with electronically collected tolls set using demand pricing. Car pools will continue to have free use of the lanes during rush hours.

Arlington County, where the northernmost third of the corridor is located, balked at previous attempts to convert the existing HOV system within its boundaries, citing concerns about increased noise and air quality issues. Late last year, however, county leaders signaled a willingness to consider VDOT’s plan, most of which will be constructed within existing right of way. The environmental assessment process for the conversion is already underway, the agency says.

Last fall, VDOT announced a 2.5-mile extension of the Express Lanes from its existing southern terminus at Garrisonville, a flyover ramp located in close proximity to an increasingly busy suburban interchange. This project aims to eliminate frequent bottlenecks that occur when heavy southbound Express Lane traffic merges back onto the I-95 mainline.

VDOT’s partner to plan, finance, and oversee design, construction, operation, and maintenance of these expansions will be Transurban, which also led development of the I-95/395 Express Lanes, and a previous HOT project integrated into the western portion of the I-495 Capital Beltway.

Plans call for construction on the I-395 Northern Extension to begin in spring 2017 with completion in summer 2019. Construction on the I-95 Southern Terminus extension could get underway as early as this summer, with a new southbound ramp opening in winter 2017/2018, and a new northbound ramp opening the following summer.

Ultimately, VDOT hopes to extend the I-95 Express Lanes lanes at least another 10 miles to Fredericksburg, currently the hub for DC’s southernmost suburbs. The agency is also exploring HOT lane options for I-66, Northern Virginia’s primary east-west corridor.