In Design: Route 50 Corridor Improvements in Fairfax and Loudoun Counties

Cost and schedule ►

This project will make safety and operational improvements at several locations along a six-mile stretch of Route 50 (John S. Mosby Highway) between Gum Spring Road (Route 659) and Centreville Road (Route 657).

The improvements include:

  • Replacing the northbound Gum Spring Road right turn lanes at Route 50 with a free-flow right turn lane and a new eastbound Route 50 merge lane from Gum Spring Road to Hutchinson Farm Drive
  • Extending the westbound Route 50 left turn lanes at Gum Spring Road
  • Extending the eastbound Route 50 left turn lane at Loudoun County Parkway
  • Converting a westbound left turn lane at Pleasant Valley Road (Loudoun) to an auxiliary through lane running to Tall Cedars Parkway
  • Improving traffic signal timing and the intersection layout at Avion Parkway
  • Improving traffic signal equipment and timing at Centreville Road

Route 50 averages up to 71,000 vehicles a day within the project limits. 

Estimated Costs
Preliminary Engineering: $1.3 million
Construction: $9.4 million
Total: $10.7 million

The project is financed with federal, state (including Smart Scale) and Loudoun County funding.


The project aims to relieve congestion and improve safety and operations.

Major Milestones 

Begin Preliminary Engineering: April 2019
Begin Construction: Mid 2024


Contact Info:

W. Calvin Britt, P.E.
Location & Design

Kimberly McCool, P.E.
Preliminary Engineering (Loudoun)

Andrew Beacher, P.E.
Preliminary Engineering (Fairfax)

Phase: In Design

UPC: 114827, 114828

State ID: 0050-053-211, P101; 0050-M10-010, P101

Federal ID: HIP-5B01 (043); HIP-5B01 (042)

Lat/Long: 38.911217, -77.473252

Locality: Fairfax and Loudoun

Page last modified: Jan. 26, 2022