Spoiler: Incessant tapping won’t make a walk sign appear any faster.
Our safety relies on them. We tap without second thought. Yet to the average pedestrian crossing the street, exactly how push-to-walk buttons work remains a mystery.
Do they send a signal to the stoplight to turn green sooner? Or, is it just a placebo to make impatient pedestrians feel like they have some control while they wait?
Full disclosure: This question came from a Seattle Times staffer. But because everyone uses the buttons, we figured the answer was worth knowing.
First, types of pedestrian-crossing systems in Seattle vary by location.
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All include a network of underground wires that send signals between the sidewalk buttons to computers connected to traffic lights.
Here’s what’s key: Most walk signs in downtown and other dense areas activate on a timed schedule, regardless of whether someone hits a button. Others require a tap to change the pedestrian signal. The thing is, there’s no foolproof way to tell which is which.
For instance, more than 30 intersections on Mercer Street — where crews installed new, adaptive traffic lights this spring — do not flash walk signs unless people call for them with the buttons.
Signals at Capitol Hill’s Broadway East and East Pike Street intersection, on the other hand, cycle automatically, even if no one pushes the button.
They typically flash a walk sign for seven to 10 seconds and red hand for 11 seconds each cycle, said Dongho Chang, Seattle Department of Transportation (SDOT) city traffic engineer.
Seattle generally follows federal guidelines for determining how long walk signs appear at intersections, and that time varies by location and is based on criteria such as street width and amount of traffic.
Timing aside, SDOT says about 15 percent of Seattle’s 1,066 signalized intersections use vibration technology and speakers to aid…