Montgomery County declares traffic light glitch fixed

Montgomery County officials Thursday night pledged a smoother morning commute after engineers fixed a glitch in the county’s traffic control system that caused a mistiming of traffic lights and gridlock during the past two days’ rush hours.

County Executive Isiah Leggett reported a “breakthrough in the repair” to the central traffic signal computer that is supposed to switch the timing of traffic lights to rush-hour mode.

“Engineers have isolated the problem and have been successful in re-establishing the connection between the computer and the traffic signals,” Mr. Leggett said. “Most of the intersection signals are now responding to our commands.”

He said county workers would continue to work on individual signals that were still malfunctioning.

“We will continue to monitor it throughout the evening and overnight, but we anticipate that tomorrow mornings rush hour will be much smoother,” Mr. Leggett said Thursday night.

The 30-year-old central traffic signal computer crashed early Wednesday morning, throwing off the synchronization of 750 traffic lights in the county. Traffic lights were operating on regular, non-rush hour timing, county officials said. They were supposed to switch to morning rush mode, from 7 a.m. to 7:30 a.m.

Tom Pogue, a spokesman for the county’s Department of Transportation, said there were several delays. He said the county directed its Ride-On bus system to provide free transportation for the inconvenience. It will continue to assist commuters on Friday.

“This is not anything we have experienced before,” Mr. Pogue said. “We are still working to isolate the problem, but we’re not sure how long it’s going to take.”

Traffic lights affected by the program failure caused significant hold-ups on Veirs Mill Road, Connecticut Avenue, Georgia Avenue and Rockville Pike, among other roadways, and they contributed to delays along Interstates 270 and 495.

Mr. Pogue said technicians formed a two-pronged approach - workers replaced hardware in the computer system until it responded properly. They also came up with a “contingency plan” involving a manual resetting of traffic lights at priority intersections.

Two years ago, the county began working on a project to update the area’s traffic light system. The project requires a $35 million investment and is expected to take six years to complete, according to county spokeswoman Esther Bowring.

“Mr. Leggett is encouraging staff to look at the plan and see how they might be able to speed up the process,” said Ms. Bowring. “It’s a complex project with many facets involved.”