Factors influencing the safety of urban residential collector roads

Abstract

ABSTRACTThis study investigated the impact of various road elements on collision frequencies for urban residential collector roads. Negative binomial safety performance functions were developed for total collision occurrence and severity using 4 years of data from the City of Edmonton. The proposed models were estimated using the maximum likelihood estimation technique. Scaled deviance and the Pearson chi-squared statistic were used to assess the models’ goodness of fit. Results revealed that the property-damage-only (PDO) collision model has the same significant covariates as the total collisions model. For predicted total and PDO collisions, there is a statistically significant positive relationship between collisions and access-point density, stop-controlled intersection density, the presence of a horizontal curve, licensed premises, seniors’ centers, and on-street parking. For severe (i.e., fatal and injury) collisions, the results were quite similar to the total and PDO collisions with some exceptions (e.g., number of lanes, bus-stop density). On the contrary, there is a significant negative relationship between predicted severe collisions and the presence of a median, center line, and manned enforcement. The city authority could use this information to assess the associated safety risk of residential collector roads and, hence, prioritize collision prone road segments.