There is a pedestrian crossing installed in Big Cottonwood Canyon in Utah, by a popular sledding hill, a few miles down-canyon of two large ski hills. It is ess

There is a pedestrian crossing installed in Big Cottonwood Canyon in Utah, by a popular sledding hill, a few miles down-canyon of two large ski hills. It is essentially an "instant" transition crossing. The moment a pedestrian triggers it, it switches on warnings, and very quickly turns to solid red stop. The solid stop lasts upwards of 15 seconds, at which point it turns to a warning stop (stop and roll through, flashing red lights). There is no cool-down period on how frequently it can trigger, and there is no platooning, so at the end of the day when everyone is going home, intermittent pedestrian traffic, say, one person every 20 seconds, is enough to back traffic up all the way to the end of the canyon. A simple bit of platooning, or a traffic detector (loops aren't good in the canyons, plows rip em up, so probably a radar based approach), would solve this, for this case at least