Identification of safety benefits by inter-vehicle crash risk analysis using connected vehicle systems data on Korean freeways

Abstract

Worldwide efforts have been made to deploy connected vehicle (CV) technologies in practice. The Korean government has also conducted various projects to fully exploit the benefits of CVs. This study attempted to estimate the safety benefits achievable of CVs based on crash risk analyses, which is a part of a pre-deployment project for CVs on freeways. A nice feature of the CVs in this project is that they are equipped with in-vehicle forward collision warning systems that are capable of providing both the speed of a preceding vehicle and the spacing between the preceding vehicle and a subject vehicle. This technical support enables us to systematically analyze vehicle interactions in terms of traffic safety. The crash potential index (CPI), which is able to analyze vehicle interactions in terms of crash risks, was adopted to quantify the crash potential of CVs when the forward hazardous situation warning (FHSW) information was either provided or not provided. The results of this study show that the average speed decreased by 10.2 % and the time-to-collision (TTC) increased by 5.3 % when warning information was provided. In addition, the achievable reduction in the CPI was approximately 20.7 % due to the provision of warning information. An illustrative demonstration of identifying freeway hazardous spots was also presented as a further application of the CPI analysis. The outcomes of this study will be useful for the establishment of relevant policies to promote CV technologies.