The answer is, weirdly enough, too much information. We all know how drivers who like to speed up at a yellow light. Countdown clock are meant for pedestrians, but they also inadvertently tell drivers about upcoming red lights—with even more detail and more lead time than yellows. While we should, in theory, act rationally with that extra information, drivers actually just tailgate more aggressively to race through before the light changes.
NPR has a fascinating story about this phenomenon based on a study done in Calgary. When the city decided to install pedestrian countdown clocks at its intersections, there were 5 percent more crashes between cars at intersections, or roughly 21.5 more collisions every month. The number of car-pedestrian crashes, however, actually went down.
via Gizmodo
Image: Cristina Muraca/Shutterstock
