About 200 traffic signals on Route 355 were out of sync Wednesday morning, creating a build-up of traffic just north of the Capital Beltway during rush hour.
Between 15,000 and 53,000 vehicles travel the affected route — which stretches from Damascus to Rockville — each day, depending on the section of the road, according to the Maryland State Highway Administration.
Discovered at 10:30 Tuesday night, the problem is believed to be a result of a thunderstorm, said County spokeswoman Esther Bowring, although the county doesn’t know for sure.
“At this point, they are focusing all of their efforts on repairs,” Bowring said.
Traffic signal syncing problems have been common in the last few years. A 2007 report by the National Transportation Operations Coalition found that traffic signal problems accounted for 5 to 10 percent of all traffic delays. At the time, all 800 traffic signals in the county were operated by a 30-year-old computer system, according to Bowring.
Although 400 of the 800 signals have now been switched over to a new computer system, the 200 signals that malfunctioned Wednesday are still on the old system, Bowring said. All traffic signals should be switched to the new system by the end of 2012.
