Take the No Love for Litter Pledge


About the Project

Route 123 Interchange

Major reconstruction is planned for the Route 123 (Chain Bridge Road) Interchange as part of the Transform 66 Outside the Beltway Project. The new interchange design:

  • Provides access to and from the future Express Lanes from I-66 East and West
  • Improves safety at the interchange
  • Connects the City of Fairfax and the planned George Snyder Trail with the new shared-use path and neighborhoods in Oakton with a grade-separated trail through the Route 123 Interchange

Get a closer look at what’s planned through the Transform 66 Interactive Map.

Route 123 Bridge Demolition

Demolition of the old Route 123 bridges over I-66 began in early January. The old Route 123 North bridge will be demolished first, followed by the old Route 123 South bridge. Most of the bridge spans are directly over I-66 and will need to be demolished during overnight hours when multiple lanes can be closed on I-66 to safely accommodate this work. Demolition activities will occur during daytime hours when possible to minimize impacts to nearby communities. 

Demolition of the two main bridges is anticipated to occur across an 8- to 12-week time frame, depending on weather and other factors. Demolition activity for each span includes breaking up the concrete bridge deck using jackhammers, sawcutters, and hoe rams, then removing the steel beams using crane lifts. After the bridge deck is demolished, crews will remove the bridge piers and abutments. See flyer for more information.

Route 123 (Chain Bridge Road) Traffic Shifted to New Bridge Over I-66

Route 123 (Chain Bridge Road) northbound and southbound traffic has shifted to the new Route 123 North bridge over I-66. The old Route 123 North and South bridges are being demolished to allow for construction of a new Route 123 South bridge, shared-use path, and new ramps to I-66 general purpose and Express Lanes.

Access to and from I-66 at Route 123 will remain in its current configuration during this phase of construction.

As construction continues through 2022 on the Route 123 and I-66 interchange, drivers should be alert for changing traffic patterns. Drivers are reminded to slow down and pay attention to lane markings and roadway signs at all times. 

The travel lanes of southbound Route 123 over I-66 shifted on to the new Route 123 Bridge on Jan. 21. Access to/from I-66 East and West will remain the same. 

Construction Update (Posted February 23, 2021)

Recent Construction Progress:

  • Route 123 traffic over I-66 has shifted to the new Route 123 North bridge (Northbound shifted on Dec. 30, 2020; Southbound shifted on Jan. 21)
  • Demolition of the old Route 123 North bridge started January 7.
  • Bridge deck and girders over I-66 East and West travel lanes have been removed.

Upcoming Construction Activities:

  • Demolition continues with daytime demolition of old bridge abutments and remaining bridge deck (not over traffic).
  • Daytime demolition of the old bridges over the old ramp from I-66 West to Route 123 South.
  • Overnight demolition of the bridge piers along I-66.
  • Construction of new Route 123 South bridge and ramps.

Traffic runs in both directions on the new Route 123 North bridge. Crews are making room for ramp connections between Route 123 and the new Express Lanes. (Mar. 1)

Only the center piers remain from the old Route 123 North and South bridges over I-66. They will be demolished later this year. (Mar. 1)

Piers and abutments are being built for the new Route 123 South bridge. (Mar. 1)

Demolition of old Route 123 bridges over I-66 finished in February. Traffic shifted to the new Route 123 bridges in January. (Feb. 17)

What Neighbors Can Expect

  • Noisy construction activities such as bridge demolition and pile driving will be avoided at night, when possible. Noise to expect at night includes back-up alarms on equipment and trucks, which is necessary to protect worker safety.
  • Lighting of the construction work area will be directed to minimize light pollution for nearby residents.
  • Project emails and website will be used to communicate major traffic switches or nighttime work.


Anticipated Schedule Dates
Clearing activities begin Spring 2018
Traffic pattern shifts begin April 2019
Ramp and bridge work begin Summer 2019
Demolition of ramp from I-66 West to Route 123 South January-February 2020
Traffic shifts to new Route 123 bridge span January 2021
Demolition of old Route 123 bridge span January-March 2021
Construction of second Route 123 bridge span begins Winter 2021
Express Lanes open December 2022


Concept plans (I-66) - PDF, 13.7MB
Concept plans (Rt. 123) - PDF, 12.6MB
Cross sections - PDF, 16.9MB
Plan and profile - PDF, 36.4MB
Planned I-66 trails near Route 123 - PDF, 1.5MB
Upcoming traffic changes (April 2019) - PDF, 424KB
Upcoming traffic changes (July 2019) - PDF, 396KB
Construction Update Meeting on September 4, 2019 Flyer - PDF, 1.3MB
Route 123 (Chain Bridge Road) South Flyover Ramp Demolition - Jan, 2020, - PDF, 5.6MB
Traffic Pattern Changes for I-66 East to Route 123 North on Feb. 21 - Website
Traffic Changes at Route 123/I-66 Interchange Starting on or about March 21 - Website
Flyer on Rose Forest Drive Closure and Detour (Sept. 2020) - PDF, 1.7MB
Route 123 Bridge Demolition Flyer (12/21/20) - PDF, 2MB