An Open-Source Virtual Reality Traffic Co-Simulation for Enhanced Traffic Safety Assessment

Abstract

Transportation safety studies identify and analyze different contributing factors affecting the safety of road users using virtual reality (VR) traffic simulations in game engines (e.g., Unity). They often either use simplified VR traffic simulation or develop a more advanced simulation requiring substantial technical expertise and resources. The Simulation of Urban Mobility (SUMO) software is widely employed in the field, offering extensive traffic simulation rules such as car-following models, lane changing models, and right-of-way rules. In this study, we develop an open-source virtual reality traffic co-simulation by integrating two different simulation software, SUMO and Unity, and developing a virtual reality traffic simulation where a VR user in Unity interacts with traffic generated by SUMO. In our methodology, we first explain the process of creating road networks. Next, we programmatically integrate SUMO and Unity. Finally, we measure how well this system works using two indicators: the real-time factor (RTF) and frames per second (FPS). RTF compares SUMO’s simulation time to Unity’s simulation time each second, while FPS counts how many images Unity draws each second. Our results showed that our proposed VR traffic simulation can create a realistic traffic environment generated by SUMO under various traffic densities. This work offers a new platform for driver-behavior research and digital-twin applications.