Bad environmental conditions may cause hazard to the drivers. Thus, most automated traffic control systems intensively use environmental data. Detection of environmental conditions involves a number of uncertainties. Therefore, conventional approaches often do not deliver satisfying solutions. This paper presents a fuzzy logic solution for the analysis of environmental conditions such as road surface condition, visual range and weather conditions. The approach is based on meteorological expertise and takes into account that detection stations are equipped with the different types and qualities of sensors. Plausibility checks are used to determine the quality of sensor signals and to compute substitute values for missing information by using other sensors. This leads to more appropriate evaluation of road surface condition and visual range to indicate slippery road condition or fog warning. The discussed fuzzy logic solution was developed for existing traffic control systems and implemented at the B27, a German state highway between Stuttgart city, Stuttgart airport, and Tuebingen. (A)
Abstract