Recently Completed: Route 606/Loudoun County Parkway/Old Ox Road

Cost and schedule ►

Note: A ribbon-cutting was held Aug. 6.

About the Project

This project reconstructed five miles of the two-lane Old Ox Road (Route 606) and widened it to four lanes between Evergreen Mills Road (Route 621) and the Dulles Greenway (Route 267), significantly improving access and capacity for commuters heading to areas such as Ashburn, Sterling and Herndon, as well as Dulles International Airport. The project also constructed a new signalized intersection at Old Ox Road and Loudoun County Parkway (Route 606/607), and a new mile-long section of the Parkway to the south and about 800 feet to the north of the intersection.

Project Background

Planning for the widening of the Route 606 corridor between Route 50 and the Dulles Greenway began in the early 1990s. The first segment was implemented in 2002-03 with the reconstruction and widening between Route 50 and Evergreen Mills Road.  

This project implemented the ‘Interim Condition’ as described in Loudoun County’s Countywide Transportation Plan (CTP), calling for Route 606 to be a controlled-access, median-divided urban collector. The ultimate condition as described in the CTP calls for a limited-access, median-divided urban arterial. The design implemented the interim condition while enabling a future conversion to its ultimate condition.


  • New signalized intersection at Old Ox Road and Commerce Center Court
  • Two new bridges, with improvements to the Horsepen Creek Dam
  • More than five miles of shared-use path along Old Ox Road for cyclists and pedestrians

Shirley/Dewberry was the contractor for the $119 million project. VDOT, Loudoun County, and the Metropolitan Washington Airports Authority (MWAA) jointly funded the Old Ox Road widening and reconstruction, with MWAA contributing about 24 acres of land for the improvements. The Northern Virginia Transportation Authority also provided $11.5 million toward improvements for the Loudoun County Parkway corridor.

Up to 26,000 vehicles a day travel Route 606 between Evergreen Mills Road and the Dulles Greenway.

Major Milestones 

  • New Old Ox Road bridge over the Horsepen Dam spillway just west of the Dulles Greenway opened to traffic in April 2017 (temporarily opened to both westbound and eastbound traffic, open only to westbound traffic in final configuration).
  • Northbound Route 606 traffic shifted onto the new ramp spur at the new Loudoun County Parkway traffic signal in August 2017.
  • Loudoun County Parkway segment north of Old Ox Road opened to traffic, and the new traffic signal at Loudoun County Parkway and Old Ox Road began operating in September 2017.
  • The four-lane segment of Old Ox Road between Evergreen Mills Road and Pebble Run Place opened to traffic in November 2017.
  • The four-lane segment of Old Ox Road from Commerce Center Court to the Dulles Greenway (including new eastbound bridge over the Horsepen Dam spillway) opened to traffic in December 2017.
  • The four-lane segment of Old Ox Road from Pebble Run Place to Commerce Center Court opened to traffic in August 2018.


Contact Info:

Sanjeev Suri, P.E., PMP

Project Photos

UPC: 97529, 105064, 105575, 107953

State ID: 0606-053-983, P101, R201, C501, B686, B687, D672, 0606-053-067, P101, R201, C501, 0606-053-085, P101, C501, 0607-053-141, P101, C501

Long/Lat: 38.970180, -77.492105

Locality: Loudoun

1 / 1
2 / 2
3 / 3
4 / 4
5 / 5
6 / 6

Page last modified: May 24, 2019