Almost every motorist knows the frustration of encountering a solid string of red traffic lights, being forced to waste time and gas when signal lights are not properly synchronized.

Indeed, frustrations over the slow drive down East Washington Street led one resident to write to a city councilmember recently asking if anything could be done to improve streetlight timing.

As it turns out, city staff has been quietly working to address the issue in Petaluma since 2009, when it started receiving grants to streamline the timing of traffic signals.

The city has recently made changes to coordinate the timing of traffic signals along Lakeville Street, McDowell Boulevard and Petaluma Boulevard and is seeing big improvements in traffic as a result, said City Engineer Curt Bates.

For instance, staff has been monitoring traffic on Lakeville Street between East Washington Street and Frates Road since it adjusted streetlights there for maximum efficiency with a 2010 grant. Since the changes were put in place, staff has seen that on average, drivers are able to travel down that road about 12 percent faster, with about a third fewer stops, achieving about a ten percent savings in gas, Bates said.

The changes are thanks to a series of $40,000 to $60,000 grants that the city was awarded in 2009 through 2011 through the Sonoma County Transportation Authority and Metropolitan Transportation Commission after it identified optimizing signal light timing as a way to improve traffic flow in Petaluma.

That money allows the city to study how to time streetlights efficiently during commute hours. Where necessary, staff has installed GPS devices that allow traffic signals to communicate with each other. Newer signals come with radio devices that also allow for communication and coordination between signals.

Bates explained that traffic signal timing will only be "optimized" during peak driving hours, typically between 7 a.m. and 9 a.m., again from 11 a.m. to 1 p.m., and from 4 p.m. to 6 p.m. The rest of the time, signals operate on a default motion sensor that registers when vehicles are at the intersection.

More traffic relief should be on the way in the coming months as well, including the areas that the resident wrote about: Petaluma received two grants in 2011 to adjust streetlight timing on East Washington Street between the downtown area and Sonoma Mountain Parkway and along Sonoma Mountain Parkway. The city waited to complete each project due to construction occurring on both roads, but changes should be in place, allowing for a smoother drive, in early 2013.