The Influence of Roadway Surface Discontinuities on Safety

It is generally recognized that discontinuities in roadway surfaces can cause problems with vehicle steering, braking, maneuvering, and response that lead to loss of control. Such discontinuities can play a significant role in the occurrence of traffic accidents and they should be considered when assessing maintenance policy, evaluating improvements. Discontinuities include deviations from the intended physical characteristics of the traveled surface that result from traffic loads, environmental effects, or other causes. In the context of this report they also include pavement edge geometry, water accumulation, and surface contaminants. The relationship between roadway surface discontinuities and traffic safety has been a topic of discussion for many years. However, except for surface friction, literature attempting to relate discontinuities to accidents is limited. The Transportation Research Board's Committee on Surface Properties-Vehicle Interaction recognized that no comprehensive effort had ever been made to compile and discuss the various kinds of discontinuities that occur in roadway surfaces and their influence on traffic safety. Consequently, a Task Group was appointed by the Committee to compile such a document. The objectives of the Task Group were to identify and discuss the safety implication of significant categories or surface discontinuities and document relevant literature for each category. The results of the Task Group's activity, contained in this report, will provide a useful resource for decision makers and others involved in providing and maintaining safe traveled surfaces.