Sign, Sign, Everywhere a Sign

Speed limits, four-way stops, traffic lights at regular intervals. These things make driving safer, right? Wrong, says John Staddon, James B. Duke Professor Emeritus of psychology and neuroscience. An Englishman who has long studied adaptive behavior patterns, Staddon argues that the preponderance of signs and signals on American roads leads us to rely on hints from traffic engineers instead of observing road conditions and fellow drivers. In the U.S., he says, "we regard this as an engineering issue. But it's really a psychological issue."

Signs warning of a sharp curve may make a particular stretch of road safer, he observes, but what happens when drivers who expect the reminder come to a curve without a sign? Four-way stops only muddle the question of who has right-of-way and may necessitate more signage at other intersections, such as warnings to two-way stoppers that "cross traffic does not stop."

Staddon is working on experiments to test drivers' behavior, but for now, comparative studies of traffic death rates between the U.S. and European countries where signage is less prominent but more consistent seem to demonstrate that, when it comes to flashing lights and warning signs, less may be more.

John Ripley