Study on the Feasibility of Vehicle-to-Infrastructure Applications Supported through Advanced Wireless Communications

Connected and automated vehicle (CAV) technology has the potential to improve transportation systems. CAV technology has been shown to bring benefits in transportation mobility, safety, and the environment. The signal phase and timing (SPaT) message is a fundamental and critical CAV message, as it enables connectivity between vehicles and infrastructure. Because SPaT messages can be transmitted using different wireless communication technologies, it is necessary to study the latency and coverage of SPaT messages in such cases. This study investigates performances of SPaT messages transmitted using two popular communication technologies in CAVs: dedicated short-range communications (DSRC) and cellular 3rd generation partnership project (3GPP)/4th generation long-term evolution (4G/LTE). To provide a robust evaluation, SPaT data transmitted by DSRC and cellular networks were collected in the field at various intersections in Northern Virginia and used to compare performance in terms of latency and distance coverage. The results showed that the latency experienced by SPaT messages over cellular networks is well below the 100 ms required by most infrastructure applications, implying that cellular communications may be used for many vehicle-to-infrastructure (V2I) safety and mobility applications. The feasibility of several CAV applications was investigated based on the network performance observed in this study. Specifically, several safety, mobility, and environmental applications were tested to determine whether DSRC and cellular networks could satisfy their requirements for network performance. The study also provides conclusive remarks on whether the wireless communication technologies are capable of supporting safety, mobility, and environmental applications.