Review of traffic safety evaluation at T-intersections using surrogate safety measures in developing countries context

Abstract

In recent years, significant research has focused on traffic safety evaluations at unsignalized intersections due to complex and heterogeneous traffic movements as well as driver behaviour at such locations. However, at unsignalized T-intersections, priority traffic rules are less respected, which creates more conflicts. Further, multiple traffic movements such as right turns and through movements with varied driver behaviour results in increases the severity of conflicts. Many research studies have focused on the proactive safety measures in traffic safety evaluations as compared to crash-based analysis. Also, it is observed that Time to Collision (TTC) and Post Encroachment Time (PET) are the predominant types of surrogate safety measures in traffic safety evaluations. From the existing research outcomes, it is understood that these surrogate safety measures may give a better understanding of chain events for crash occurrences, collision mechanisms, and resulting consequences. However, further research is required in order to understand the suitability of such surrogate safety measures based on the complexity of heterogeneous traffic as well as driver behaviour with considerations of turning vehicles, particularly at T-intersections. In this context, this paper critically reviews the recent developments in Surrogate Safety Measures (SSM) and their applications at unsignalized intersections, with a particular focus on the T-intersection. This paper also brings attention to T-intersection safety evaluation with SSM in a developing country context. The outcome of the present study is more useful in the evaluation of traffic safety at T-intersections and suitable safety indicators for the evaluation.