The impact of road alignment characteristics on different types of traffic accidents

Abstract

Among the factors affecting road traffic safety, road alignment characteristics are often ignored by people because they cause traffic accidents in an indirect way. In view of this problem, the total number of accidents, the total casualties of accidents (deaths, minor injuries, serious injuries), and the total time of road closures were chosen as road safety evaluation indices and ranked by the technique for order preference by similarity to an ideal solution (TOPSIS) method. The road sections whose ranking index value C < 0.8 were identified as accident blackspots. On this basis, the slope direction, absolute value of the elevation difference, Standard Deviation of elevation, curve radius, and transition curve ratio were chosen to describe the characteristics of road alignment. Combined with historical accident data, binary logistic regression models were established to analyze the effects of alignment factors on the frequent occurrence of three accident types (rear-end, hitting the fixture, rollover).