Commuters who drive through the intersection of U.S. Route 50 and Loudoun County Parkway, Virginia State Route 606, are familiar with the stop-and-go traffic and a history of crashes where left turns cross fast-moving traffic.

The Loudoun County Board of Supervisors is set to vote Tuesday on a major redesign of the intersection, which is an entry point to the South Riding development and adjacent to two shopping centers.

The plan under consideration, in an agenda item, would replace the four-way intersection with a “Single Point Urban Interchange,” or SPUI. In this setup, drivers on Route 50 would travel over a new bridge, while people turning onto or off Route 50 would exit and travel underneath.

The new design is meant to separate high-speed traffic from drivers making turns, according to the agenda staff report.

County inspections have determined “the at-grade intersection of these roadways is operating at a failing level of service during all peak periods,” according to the report.

Plans to deal with the intersection have changed over the years. In 2016, the board endorsed a full cloverleaf design to replace the intersection.

However, changes in nearby development, along with updates to the nearby Dulles International Airport’s master plan, make the cloverleaf design less practical, county staff wrote. The Metropolitan Washington Airports Authority supports the new Single Point Urban Interchange approach, according to the board.

The proposal also calls for a new 10-foot-wide path for pedestrians and bikes on the west side of Loudoun County Parkway between Riding Center Drive and Arcola Mills Drive.

County documents said construction would require some land acquisition, but the new layout should reduce the amount needed compared to earlier designs.

The project budget is about $299 million, which covers planning, design, land and construction costs, according to board documents.

Source