Dear Cecil: Why are there pushbuttons at intersections that say “push me and traffic will stop so you can cross quicker,” or something like that? It doesn’t work! I wouldn’t say I’m neurotic about it, but about 15 years ago I quit my job to hitchhike around the USA to find a push-to-walk traffic signal that would actually stop traffic. After countless pairs of shoes and as many near-misses with cars, I can say that without a doubt none of these traffic signals provide the pedestrian with a quicker cross. What’s going on? If I’m right maybe we can work some kind of lawsuit scam! Markus T. Pellicori, Baltimore
I like a man who takes things seriously, Markus, but just the same I’m glad you weren’t my partner in chem lab. The usual explanation for the apparent inertness of push-to-walk buttons is the foolish expectations of users, who think the buttons will instantly bring traffic to a screeching halt. Satisfying though many hassled pedestrians would no doubt find this, it would also result in a lot of rear-end collisions. Instead, P-T-W buttons are set up so the "walk" signal lights at some nondisruptive point in the signal cycle, e.g., shortly after the previous signal up the street goes red. Since many suburban stoplights are on a two-minute-plus cycle, many impatient pedestrians erroneously conclude the button is broken.
Or so the engineers say. However, Cecil has been lied to before. I decided the only way to be sure was to stake out an actual P-T-W button, which happened to be at the crosswalk (no cross street) outside the traffic court building in downtown Chicago. During the Friday afternoon rush I spent half an hour pushing that damn button without any observable effect at all. It was 25 seconds "walk," 50 seconds "don’t walk," button or no.
At 11 PM it was a different story. The "walk" signal didn’t light unless you pushed the button, in which case the signal changed a second or two after the light went red at the previous signal up the street. Problem was, at that hour there were hardly any pedestrians, and the few there were didn’t bother to push the button, no doubt having been burned by the signal’s nonresponsiveness at 5 that afternoon.
Conclusion: push-to-walk buttons only work when there’s nobody around to push them. To put it more charitably, the buttons generally are wired to insert a "walk" phase into an otherwise walkless signal cycle, not speed an existing "walk" phase up.
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