Modeling Safety Performance of Urban Roads with Heterogeneous Traffic Conditions

A 2.9-mi corridor of US 29 (N. Tryon St.) comprising of Lynx Blue Line light rail transit (LRT) in the city of Charlotte, North Carolina, was considered for the analysis. A base simulation model with existing traffic conditions and LRT for the year 2018 was modeled in PTV Vissim microsimulation platform. Hypothetical scenarios with different penetration of non-motorist traffic (pedestrians and bicycles), different frequency of LRT, and change in the vehicular traffic volume were modeled to assess the effect of various modes on traffic safety performance using surrogate safety assessment model (SSAM). The evaluation is based on the conflicts between the road users during the simulation runs from the trajectory files in PTV Vissim. Notable effects on safety performance were observed across different scenarios, emphasizing the need to plan and build infrastructure by evaluating complex mobility patterns and interactions between all the road users. The methodological framework used in this research is cross-disciplinary, transferable, and can be applied to other regions.