Enhancing Safe Traffic Operations Using Connected Vehicles Data and Technologies

Abstract

This research focused on using connected vehicle information to identify locations prone to conflicts between motorized and non-motorized users to improve traffic safety on mixed-use roadway networks. With this information, transportation system users can be alerted of potential conflicts prior to their occurrence, allowing them to take preventative actions, perhaps by making evasive maneuvers. A comprehensive review of the literature was made to investigate existing vehicle-to-X (V2X) safety applications. The methods to allow a sensor to communicate via both dedicated short range communications (DSRC) and Bluetooth, WiFi, or another communication protocol commonly used by mobile devices were also investigated, as were existing surrogate safety measures and their use in conflict- and safety-prediction algorithms. The review indicated that several studies have focused on the safety and operational benefits of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications; however, the safety benefits of V2X communications have not been sufficiently explored in published materials so far. In this project, a cost-effective, solar-energy driven, small, and lightweight communication node device, called the smart road sticker (SRS), was developed to communicate with connected vehicles via LoRa and DSRC, and with pedestrians, bicyclists, and unconnected vehicles through cell phones and other mobile devices via Bluetooth. A mobile application that allows pedestrians, bicyclists, and drivers of unconnected vehicles to communicate with the SRS device and vice versa was also designed. A crash prediction algorithm was developed to identify unsafe conditions and to determine appropriate, CV-based safety countermeasures to be presented to system users. Finally, a connected vehicle simulation test bed was established in VISSIM to evaluate the safety benefits of the proposed methodology under various traffic and landscape conditions. This study found that the number of conflicts increased when penetration rates decreased. In addition, increasing volumes had a direct relationship with an increase in the number of conflicts.