Comparative Analysis of Methodologies for In-built Network-wide Road Safety Assessments

In-built Road Safety Assessment(IRSA) consists of evaluating the safety performance of the sections within the road network based on the design, operation and maintenance characteristics of the road. This is a proactive assessment method that can identify, evaluate, and classify risks on the network even before a crash occurs. It is the most widely accepted approach for road network assessment. The new EU network-wide IRSA methodology differs from existing methodologies in terms of network segmentation, risk index, and safety ranking. As a result, the objective of this study is to compare the efficiency of this novel methodology to the simplified methodology proposed by the World Bank for IRSA. Both assessments are conducted on the same road network, considering the same road attributes and safety quantities. Findings indicate that the EU proactive approach identified more critical road sections than the World Bank methodology, which is very significant at this moment as road practitioners engage in performing network-wide assessments to meet-up with the European Commission deadline. This study informs road engineers and practitioners on the efficiency of IRSA methodologies in evaluating the safety performance of road networks, resulting in the proper identification of high-risk sections.