Question: I seem to get caught at almost every traffic light in Tacoma while trying to drive across town. Does the city not synchronize the lights in an effort to keep traffic moving smoothly? -- Brian, Tacoma
Answer: Youre apparently not doing it right, Brian, because the city does in fact synchronize most of its 327 traffic signals.
Thats according to Joe Nollan, Tacomas traffic field operations supervisor.
Signals on most arterials generally are set to change to green 15 seconds after the preceding signal goes green, Nollan said.
That could change depending on the direction youre traveling and the time of day, he added.
Traffic engineers try to keep traffic moving more efficiently on routes headed into the city during the morning drive, out of the city during the evening drive and to strike a balance at midday, Nollan said.
Its also a numbers game, he said. Most signals operate in a 100-second window. That means the signal has 100 seconds to give a green to all four directions, he said.
Gotta give everybody a green light for some period of time, Nollan said.
Still, the priority is for the most heavily traveled streets to get the green the longest, he said.
Of course theres one variable that can mess up the best laid plans of both traffic engineers and commuters, Nollan said, and thats traffic.
All the synchronization in the world cant help you if the streets are clogged with other drivers.
Adam Lynn: 253-597-8644
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