An anonymous reader writes: Traffic engineers had a problem to solve: too many pedestrians were getting hit by cars while using the crosswalks at intersections because they didn't know when the 'WALK' sign would change. Their solution was simple: implement a countdown timer. Countless cities have now adopted these timers, but it turns out to have an undesired consequence: motor vehicle crashes are actually increasing at intersections where the countdown timer is used. Researchers think this is because pedestrians aren't the only ones who see the timers. Drivers see them too, and it provides them with information on when the light will change. Then they anticipate the change by either speeding up to beat a change to red light, or anticipating a green light in order to get through before the pedestrians can move into the road. The researchers suggest finding some way to hide the countdown from the drivers, perhaps through the use of an audio countdown that would be difficult to hear from inside a car.