EVALUATING THE IMPACTS OF PAVEMENT SURFACE DEFECTS ON TRAFFIC SAFETY: A CASE STUDY OF ARBA MINCH TO ZEYISE WOZEKA ROAD, ETHIOPIA

Abstract

Traffic accident is increasing enormously globally day to day. For the developing countries like Ethiopia road traffic accident is among the main economic, social and political problems. Numerous amount of research had been carried out on traffic accident. Few researchers studied the effect of road surface condition on traffic accident. The number of researchers put a lot of factors that might increase the traffic accidents. The most critical factors were drivers, vehicle condition, roadway conditions and environmental conditions. The hardness to maneuver, the problem to take and give lane for other vehicles, discomfort of drivers and so on are the main factors of the road surface defects causing road traffic accidents. So that this research is initiated to evaluate the correlation of road surface condition to road traffic accidents. The severity of the surface defects were collected from condition survey and the number of accident data of study area has been collected from Gamo Gofa zone road and transport office and Arba Minch zuria traffic police directive. The multiple linear regression model has been done for analysis of each study stretches by taking the number of road traffic accidents as dependent variables and the road surface defects as independent variables. Strongly correlated road surface defects to rate of accident were edge break, potholes, rutting and roughness. In addition to this the pavement condition index is calculated in order to distinguish the category of the road pavement current condition. Road pavement condition category is the qualitative measure and this qualitative data had been quantified from 0 to 5 which assigned to the pavement condition score. The effects of this quantified numerical road surface condition on road traffic accident was modeled by using multiple linear regression. The modeled analysis indicates that the statistical indicators shows good fittings. The study concludes that highest accident rate occurred at the road stretch which had very poor pavement condition and lowest Pavement Condition Score. The increase in pavement defects also increases the rate of traffic accident. Finally the study forwarded engineering solutions and recommendations for the improvements of traffic safety.