Application of Simulation-based Traffic Conflict Analysis for Highway Safety Evaluation

Highway safety evaluation is one of the critical processes for identifying transportation system performance. The capabilities of common used safety assessing methodologies such as naïve before-after comparisons, safety audit, and statistical modelling, etc, are limited due to historical data availability, observation periods, or observer’ experience, and so on. Other than these traditional methods, it has been recognized that the development of traffic conflict techniques in conjugate with micro-simulation model could also offer a potentially innovative way for conducting safety assessment of traffic systems even before safety countermeasures are actually implemented. So in this paper, the application of this new method on highway safety analysis is further investigated. In the meanwhile, most of recent developed safety indicators are reviewed. Inspired by these potential safety indicators in support of traffic conflict analysis, a new time-based indicator is proposed. And the procedure describing the imputation procedure is presented. As an extension of previous study, the new indicator is tested under two different highway models to further highlight its performance. Other than the capability of capturing real crashes’ temporal distribution feature showed in previous study, the comparative results also successfully identified the spatial distribution feature of real crash; especially highlight the most dangerous locations. Thus it is suggested that the new indicator has the capability to be applied for simulation-based safety analysis.