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ALEXANDRIA, Va. — Drivers along Duke Street should expect brief signal flashes and possible delays this week as city crews install new adaptive traffic signal cabinets at two of the corridor's busiest intersections.
The work is scheduled for Duke Street and N. Quaker Lane on Tuesday, April 21, and Duke Street and S. Quaker Lane on Thursday, April 23. It is part of the city's Adaptive Signal Control Cabinet Upgrade project, a component of Alexandria's broader Smart Mobility Program.
Unlike the city's current signals, which run on preprogrammed schedules tied to the time of day, the new system uses video and LiDAR-based detection to monitor conditions and adjust timing in real time. A central system uses that information to shorten wait times and coordinate timing throughout the corridor. Once fully deployed, officials say the technology will reduce congestion, improve travel time reliability, and keep intersections running more smoothly during peak hours, incidents, and weather events.
City officials trace the project's origins to the rise of navigation apps, which began dynamically rerouting drivers and disrupting the predictability of traditional signal timing. Alexandria secured more than $14.5 million to carry out the work in two phases. Phase I, now underway, is placing signals along Duke Street and S. Van Dorn Street under adaptive control. Phase II will extend the technology to additional corridors and is expected to begin construction in 2028.
Construction on Phase I began in summer 2025, with crews installing conduit and pulling cable across intersections in the project limits. Substantial completion is anticipated in spring 2027.
The city is asking residents and commuters to plan extra travel time or use alternate routes during the installation work.
"We appreciate the community's patience as we work to improve traffic with new technology," the city said in its project update.
Officials are also urging motorists to slow down and follow the direction of signs and flaggers in active work zones. Drivers can check conditions in advance through the Virginia Department of Transportation's 511 tool at 511.vdot.virginia.gov, through the free 511 Virginia mobile app, or by calling 511 from any phone in Virginia.
Additional Duke Street intersections are slated for upgrades in the coming months, including the Alexandria Commons entrance, Sweeley Street, Roth Street, Witter Street, W. Taylor Run Parkway, S. Dove Street, Callahan Drive, Diagonal Road, John Carlyle Street, S. Peyton Street, and West Street.
City officials describe the project as a step toward a more responsive transportation system and a foundation for future connected and automated vehicle technologies in Alexandria.
