Multi-criteria decision making techniques for combining different sets of road safety performance indicators into an overall index

Abstract

With the ever increasing public awareness of the complexity of road safety phenomenon, more detailed aspects of crash and injury causation rather than only crash data (e.g., the number of road fatalities) are extensively investigated in the current road safety research. In this respect, safety performance indicators (SPIs), which are causally related to the number of crashes or to the injury consequences of a crash, are rapidly developed and increasingly used. Furthermore, to measure the multi-dimensional concept of road safety which cannot be captured by a single indicator, the exploration of a comprehensive composite road safety performance index is attractive and desirable. The index can thus present an overall road safety picture by capturing a multitude of risk information in one index score, and offers advantages in terms of communication, benchmarking, and prioritizing road safety actions. In this study, the TOPSIS (Technique for Order Preference by Similarity to Ideal Solution)