Question: Robert Staeger of Vancouver is curious about a new type of traffic signal he’s encountered.
“Recently I observed in the Hillsboro, Ore., area left-turn arrow signals changing to flashing amber after a short period (apparently allowing for the initial wave of oncoming traffic to pass through). This seems like a good idea to me. Is this a new idea? Is it done in Washington State?”
Answer: The flashing yellow left-turn arrows have started to appear nationally in recent years. The new left turn signals have four phases: green (protected turn), solid yellow (prepare to stop), red (stop) and flashing yellow, which permits a left turn, but only after yielding to pedestrians and oncoming traffic (which has a green light). Trial studies showed that the lights were effective in reducing motorist confusion and traffic accidents, while improving traffic flow.
Oregon localities, including Washington County west of Portland, were among the first to embrace the new signals. And they’ve spread to several Washington locations, including Kitsap County, Everett, Bellevue, Kennewick and Vancouver.
Federal Way piloted its first yellow flashing yellow arrow signals in 2006, shortly after federal and state authorities begin allowing them under an interim rule, according to Rick Perez, the city’s traffic engineer. The city just turned on its ninth last week and had plans to install more in the next year.
A comparison of accidents before and after the conversions showed an overall improvement in safety in Federal Way. “Like most traffic changes, initially there was some negative comments, but those have died away, and now we mostly get requests for more of them,” Perez said.
Expect to see more flashing yellow arrows in the wake the Federal Highway Administration’s full approval last year.
“I’m excited about the benefits being realized, and hope that more agencies jump on this bandwagon,” Perez said.
Here’s a link to a cool animation of the signal.
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