Work zone safety intervention: Perceptual countermeasure to speeding using synchronized warning lights

A driving simulator study of perceptual countermeasures to speeding is described. Perceptual countermeasures (PC) manipulate the drivers' visual scene to help them moderate their driving speed without a conscious deliberation to do so. The use of synchronized warning lights in work zones as a PC is similar to airplane runway lights flashing toward the diver. Based on the literature survey, this effect was postulated to make drivers think they were driving fast at lower vehicular speeds with lesser speed fluctuations. The effect did not achieve statistical significance in reducing mean speeds within work zones to match the posted speed limit. A frequency domain analysis of driving speed fluctuation within work zones demonstrated that any form of flashing lights can have a pronounced effect on some individuals compared to static lights. The ramifications of using such perceptual countermeasures, which are currently being implemented around the world, are discussed.