Identifying the risk factors affecting crash severity at intersections with considering crash characteristics and signal configuration using an ordered logistic model

Intersections are critical places which experience high levels of accidents due to the availability of vehicle movements from different directions. Therefore, there is a need to understand the factors that significantly contribute to injuries at such places. These factors can fall under different dimensions in traffic safety such as environmental conditions, road user behavior, traffic police enforcement, road design and crash characteristics. The paper will analyze the factors related to crash characteristics and traffic signal operation that affect the likelihood of accident severity located at intersections. The data for intersection accidents in Abu Dhabi from 2013 to 2016 were used in this analysis. Ordinal logistic model was considered for the analysis to account for the ordinal nature of severity levels. Several diagnostics tests of the model were preformed such as parameters evaluation, overall model evaluation and prediction accuracy. For parameter evaluation, out of 11 independent variables, 6 were non-significant and dropped from the model. Most of the non-significant variables were related to the driver-at-fault details. The results of the final model showed an overall good fit based on a p-value of less than 0.05, as well as a good accuracy of prediction 84.8%. Finally, odds ratios were estimated to interpret the final results of the model.