One of northern Virginia’s most congested commuter corridors is finally getting some additional capacity, with the start of construction on a $79.5 million widening project for State Route 28 in Fairfax County.

Shirley Contracting Co., lead contractor for the design-build project will add a travel lane in each direction along the existing 2.3-mile, four-lane highway between the U.S. Route 29 interchange and Bull Run at the Prince William County line. Along with incorporating provisions for further expansion in the future, the project will also upgrade five signalized intersections and install soundwalls alongside adjacent residential areas.

Increasingly burdened with growing traffic volumes topping 60,000 vehicles per day over the past decades, the section has been a source of frustration among area motorists, particularly since other sections of Route 28 to the north and south have been expanded via separate projects over the years.

“If it’s the last section to get widened, there’s a reason for it,” says Steve Kuntz, vice president and manager for the Fairfax roadway design group of Dewberry, the design-build team’s engineer.

Kuntz explains that numerous utilities share the Route 28 right-of-way, including a major water line locates directly beneath the pavement. Adjusting the roadway’s profile will avoid the need for relocation work, he adds, while a special drainage strategy will minimize excavation at a major natural gas line crossing.

Environmental issues also complicated the project, as the widening will span seven wetlands and five waterways. Impacts have been limited to 1,800 sq ft of wetlands, which will be offset with the purchase of wetland bank credits.

The project team will be required to maintain four lanes of traffic during peak travel hours throughout construction, which is scheduled for completion in mid-2023.