Cause Analysis of Traffic Crashes Black Spots on Highway Long Steep Downgrades In China

Traffic crashes occurring on long steep downgrades of highway is very frequent and severe in China. Crashes aggregate on some special places where black spots are formed in this kind of highway sections. Causes of traffic crashes black spots on long steep downgrade need to be analyzed in order to improve the traffic safety performance in those places. Based on the investigation of traffic crashes data of 5 years period occurring on a typical expressway in South China with long steep downgrades, the expressway infrastructure traffic safety performance was analyzed before and after the traffic safety countermeasures applied by crash aggregation analysis method. And based on a brake temperature transformation model of trucks, causes of traffic crashes black spots on the long steep downgrade of that expressway were analyzed. Overload was given as a main cause of those traffic crashes black spots. The findings were helpful to understanding the cause of the crashes deeply and defined the most useful traffic safety countermeasures on that kind of black spots.