THE IMPACT OF PAVEMENT CONDITION ON ROAD SAFETY IN NEW BRUNSWICK

This study developed an understanding of the relationship between pavement condition and road safety on rural arterial and collector roads in the province of New Brunswick. The intent was to use this relationship for consideration as a decision-making criterion in asset management programs. Two crash prediction models were developed for single-vehicle and multiple-vehicle collisions using a negative binomial regression that relates pavement condition indicators to accident frequency. International Roughness Index was found to be significant in both models which indicate that IRI is a contributing factor to single-vehicle and multiple-vehicle accident involvements. It is noteworthy that the model coefficient for IRI was determined to be negative in both models which reflects that a higher number of collisions is expected to occur on road sections with smoother pavement surfaces. Crash modification functions were developed for both single-vehicle and multiple-vehicle collisions. The results indicate that a unit of increase in IRI in m/km is expected to decrease single and multiple-vehicle accidents by 7.7% and 14.8%, respectively. It was also found that the percentage of change in multiple-vehicle collisions due to pavement roughness changes, while all other variables in the models remain constant, is approximately two times greater than the percentage of change in single-vehicle accidents. According to the crash modification functions (CMF) associated with pavement age, the results indicated that collector roads are slightly more impacted by pavement roughness than arterial roads.