On October 3, 2002 the Virginia Department of Transportation (VDOT) signed a Comprehensive Agreement with The Clark Construction Group, Inc. and its road and bridge construction subsidiary, Shirley Contracting Company, LLC to develop, design and build six high-capacity grade-separated interchanges on Route 28 in Fairfax and Loudoun Counties. Improvements to the corridor are vital to the continued economic development of the fast-growing area that is home to Dulles International Airport, AOL Time Warner Headquarters and the Smithsonian's new Air and Space Museum.

The agreement provides a combined commitment of $200 million in improvements to the Route 28 corridor over the next four years. Ultimate plans call for constructing a total of 10 interchanges and widening Route 28 from six to eight lanes between Route 7 and Interstate 66. The initial six interchange upgrades include Route 606, Route 625 and Sterling Boulevard in Loudoun County, and Air & Space Museum Parkway (formerly Barnsfield Road), Westfields Boulevard and McLearen Road in Fairfax County. Route 28 Corridor Improvements, LLC (the Clark/Shirley team) is responsible for right-of-way acquisition, utility relocation, site development, design and construction services.

The project is being built under Virginia's Public-Private Transportation Act, which allows private entities to propose innovative solutions for designing, building, financing and operating transportation improvements. VDOT will contribute state highway funds, and revenue bonds backed by proceeds from the Route 28 Tax District will be utilized to finance the balance of the project. Landowners along Route 28 agreed to pay for improvements to the corridor in 1988 through a special tax district.

Loudoun County, Virginia is the second fastest growing county in the nation. More than 100,000 cars a day use the segment of Route 28 just north of the Dulles Toll Road. By 2012, transportation officials estimate that segment will carry 200,000 cars a day.