Construction ramps up to replace Hunter Mill Road bridge near Vienna

Construction is ramping up today (Sept. 14) on the $5.2 million project to replace the one-lane Hunter Mill Road bridge that runs over Colvin Run near Vienna.

A new two-lane bridge where Hunter Mill crosses Colvin Run right near the border of Reston and Vienna is set to replace the nearly five-decade-old, weight-restricted one-lane bridge currently there.

While construction began a year ago, this week marks the beginning of using temporary traffic signals and Driveway Assistance Devices (DADs) in the vicinity of the bridge to allow crews to complete construction on the new bridge. Those will be in place until the new two-lane bridge reopens to traffic in the spring of 2023.

Vienna: Around noon Wed 9/14, temporary traffic signals and Driveway Assistance Devices (DADs) will be activated along Hunter Mill Rd in the area of Colvin Run to allow construction to continue on the new bridge. Sadly, these DADs won't have jokes. More: https://t.co/RnOKQkydae pic.twitter.com/aZACjX6nUw

— VDOT Northern VA (@VaDOTNOVA) September 12, 2022

The existing bridge was built in 1974 and is being replaced both because it’s in need of major repairs and to help with traffic, per Mike Murphy with the Virginia Department of Transportation.

“The new bridge will have two lanes, thereby improving traffic flow as traffic in one direction will no longer have to yield to the other when crossing the bridge,” Murphy told FFXnow.

That section of Hunter Mill Road averages about 7,400 vehicles per day.

Beyond a new bridge, there will also be a landscaped median/splitter island and abutments for a new trail bridge over Colvin Run. Fairfax County is responsible for the trail bridge and it’s expected to be built in the future.

The project is costing $5.2 million in total, including $1 million for engineering and $4.2 million for construction. Funding is a mix of federal, state, and county funds with the state contributing about $3.3 million from its State of Good Repair program and the county about $400,00 to the project, per Murphy.

The full VDOT press release on the use of temporary traffic signals and DADs:

Temporary traffic signals on Hunter Mill Road (Route 674) will be activated just north and south of Colvin Run around noon Wednesday, Sept. 14 as part of the Hunter Mill Road over Colvin Run bridge project, according to the Virginia Department of Transportation.

The transition points from two lanes to one on Hunter Mill Road will be moved further away from the bridge. For traffic coming from the Dulles Toll Road (Route 267), the transition to one lane will occur before the Lake Fairfax Park Maintenance entrance; for traffic coming from Baron Cameron Avenue (Route 606), the transition to one lane will occur before the residential access road located just north of the bridge. Relocating the transition points will allow the second lane of Hunter Mill Road to be constructed along and adjacent to the bridge.

Also, three Driveway Assistance Devices (DADs) will be installed: one at the Lake Fairfax Park Maintenance entrance, one at the residential access road just south of the bridge (opposite the maintenance entrance) and one at the residential access road just north of the bridge. The DADs will allow drivers turning onto Hunter Mill Road to see which direction traffic is moving between the two temporary traffic signals.

The temporary signals and DADs, which will efficiently manage the one lane of alternating traffic in each direction on Hunter Mill Road and traffic from the side entrances, will be in place until spring 2023.

The traffic pattern changes are part of the project replacing the weight-restricted (10 tons) one-lane Hunter Mill Road bridge over Colvin Run. The bridge was originally built in 1974. The new bridge will have two lanes separated by a median/splitter island. The project also includes an improved trail crossing south of the bridge, landscaping in the median/splitter island and abutments for a new trail bridge over Colvin Run (Fairfax County will construct the trail bridge at a future date). The project is scheduled for completion in spring 2023.

Visit the VDOT project page for more details.

Drivers, cyclists and pedestrians are reminded to use caution when traveling in active work zones. Be alert to new traffic patterns and limit distractions.

You can get real-time traffic, work zone and incident information online at 511virginia.org, via the free mobile 511Virginia app, or by calling 511 in Virginia anywhere anytime.

View this release online.

Follow VDOT Northern Virginia on Twitter: @vadotnova