Virginia DOT Times Traffic Signals To Smooth Commutes
Virginia's Department of Transportation Tuesday began re-timing stoplights at 40 intersections in the congested Tysons Corner area west of the Washington, D.C., Beltway.
To improve traffic flow, VDOT used optimization and simulation software -- Synchro and SimTraffic from Berkeley, Calif.-based Trafficware -- to better synchronize signals. "It took 10 minutes to compute all the re-timings, and it took five months to collect the data and put it into the system. That's the power of technology," said Jeris White, VDOT's signal system manager.
Speaking from the roof of a Tysons Corner information technology consulting firm, White said VDOT must revisit traffic signal timing at least every two years. "We collect information on traffic volume, speeds, intersection geometrics, and we put that information into software tools to compare baseline and optimum traffic signal plans," he said.
VDOT optimized the 40 traffic signals as a network, re-timing the lights for the morning and afternoon rush hours as well as for mid-day, evening, weekend and off-hour traffic. About two-thirds of 40 intersections were re-timed for the afternoon rush hour by 3 p.m. Tuesday, but it will take about two weeks to fine-tune the system.
-- Meg Misenti (firstname.lastname@example.org)