Increasing Road Safety by Influencing Drivers' Speed Choice with Sound and Vibration

This paper discusses road safety issues and the necessity for safety enhancements, especially on rural roads. Points of discontinuity in infrastructure consistently lead to serious accidents. The major causes of these accidents are inattentiveness and excessive speed. A possible measure to increase attention and reduce speed is installation of transversal rumble strips (TRS). The German government funded a research project to evaluate the use of these strips in the approaches to hazardous bends. The design of rumble strips was optimized on the basis of literature research and metrological preexaminations. The resulting design is expected to create a maximal impact on the driver. The effect of these optimized rumble strips on speed choice was tested by field studies. In the approaches to hazardous bends on rural roads, rumble strips were installed according to the design of the pretests. The impact on the drivers' behavior, especially on speed choice, was investigated by before-and-after analyses with radar measurements and video surveying. In addition to statistical analyses of the effect on the driving speed, detailed investigations on the impact to special driver groups and car types were performed. According to the analysis made in this research project, TRS are cost-efficient and have a positive effect on driving behavior and hence on road safety.