Roughness, Holes, and Bumps

This review of the literature found that most people are aware of extreme cases of roughness, such as the potholes and severe bumps, and that the effect of these surface irregularities on safety is widely recognized. The hazard of a washboard road where a driver can lose control of a vehicle at inappropriate speeds is readily understood. The transition of a roadway from a smooth surface to a rough one, however, may give a driver difficulty in controlling the vehicle and can be more subtle in its influence on safety. By violating driver expectancy, a road that is differentially rough may be less safe than a uniformly rough road.