• Location: Loudoun County, Virginia

Under a general engineering services contract for Loudoun County, B&N prepared traffic studies to determine the potential impacts a new commuter rail transit station and an associated new bridge would have on the planned roadway system in a rapidly developing area in Loudoun County, Virginia. The Route 772 Connector Bridge, expected to be completed in 2020, will cross over a new metro line and the four-lane Dulles Greenway toll road. Metro stations will be located adjacent to two new developments - Moorefield Station and Loudoun Station.

Before the bridge was planned, traffic studies had been completed and approved for both developments. Recent studies conducted by B&N compared the traffic operations of the approved roadway network to the newly proposed network with the Route 772 Connector Bridge.

The study included a total of 39 intersections – 31 at Moorefield Station and eight at Loudoun Station. The B&N team analyzed the traffic impact for each development using four different scenarios – existing conditions, no build conditions, build conditions with the bridge and build conditions without the bridge.

Study results found that there was not a significant difference between the estimated operation of the approved roadway network and the alternate network with the bridge. B&N recommended minor revisions to the existing traffic plans. Recommendations included a number of new turn lanes, new and modified roadway approaches and changes to traffic control at several intersections.