Some still see red over plan for traffic lights

A program to better synchronize the region’s traffic signals is speeding along ahead of schedule, but regional transportation officials wonder whether drivers are doing likewise.

In 2002, Transportation Planning Board members asked local transportation departments to embark on a mission. The goal: having 3,000 traffic lights in sync by 2005.

A report presented yesterday said 3,200 signals have been reset.

“What this means in layman’s terms is we want to minimize the number of red lights,” said board Chairman Phil Mendelson, a D.C. Council member.

But Mr. Mendelson asked how they know the changes are optimizing the lights. He said he still waits for one light to change, only to get to the next corner and find another one turning red, and it has happened to him on major routes including Pennsylvania Avenue.

“I think we can do better,” he said.

A traffic researcher cautioned that optimization does not mean all green lights, because they still have to allow for cross traffic and pedestrians.

“In a region like this, I don’t think we’re going to move toward nirvana of all green lights, but we do have tools,” said Andrew Meese, a Metropolitan Washington Council of Governments traffic researcher.

Mr. Meese said before and after field observations and computer analysis shows delays have been cut between 5 percent and 20 percent.

Georgia Avenue from Gold Mine Road in Olney to State Route 410 near the D.C. line stretches 14 miles. The trip used to take 35 minutes and 20 seconds. After the light updates, it now takes 33 minutes and 29 seconds, about a 5 percent reduction in travel time.

Optimizing the traffic lights costs about $3,000 per signal. The Maryland State Highway Administration estimates a savings of $10 in time and fuel for each $1 spent fixing the signals.

Although the time saving to the average commuter amounts to less than five minutes, Mr. Meese said, the reduced time spent idling adds up to big savings for the region’s air quality. He said the signal changes are keeping more than half a ton a day of nitrous oxide emissions out of the air.