Impact of Rural Roads Crash Modification Factors on Urban Road Safety Assessment Methodologies

Inbuilt road safety assessment procedures predict the safety levels of road sections by quantifying and ranking road safety risks per section. These risks can be estimated qualita tively or quantitatively, however, most existing procedures commonly employ Crash Modi fication Factors (CMF), for quantifying risks. However, current procedures developed for the assessment of urban roads, do not differentiate between CMFs for rural and urban roads during the process of assigning scores, which indicates that rural road CMFs are being ap plied to predict the safety levels of urban streets. In this regard, the main objective of this study is to investigate the impact of rural road CMFs in the safety assessment of urban roads. The analysis was performed based on the Proactive score model found in the Euro pean network-wide road safety assessment methodology. The study found a higher simila rity in the safety performance levels for urban road sections using both sets of CMFs, how ever, road sections assessed with rural road CMFs appeared to be safer than when urban road CMFs were applied. The correct ranking of road sections can significantly affect the allocation of road safety investment budgets, generating financial losses. These results are very relevant to safety technicians and practitioners as well as road agencies charged with conducting safety assessments.