Simulation Study Found That a 25 Percent Connected and Automated Vehicle (CAV) Market Penetration Rate Can Reduce Freeway Traffic Conflicts by 42.5 Percent During Hurricane Evacuation Operations in Florida.
Researchers Used a Microscopic Simulation Model to Emulate the Impacts of CAV Applications on I-75 Between Ocala and Gainsville During Hurricane Irma.
Gainesville, Florida, United States
Ocala
A Co-Simulation Study to Assess the Impacts of Connected and Autonomous Vehicles on Traffic Flow Stability during Hurricane Evacuation
Summary Information
With hurricanes posing risks to lives and infrastructure in U.S. coastal communities, improving traffic management strategies is key to safer, more efficient evacuations. This study applied a co-simulation approach by integrating the microscopic traffic simulation model with a communication simulator to mimic the realistic effect of Connected and Automated Vehicles (CAVs) on evacuation traffic. The study area included a segment of the interstate I-75 in Florida to represent real-world evacuation traffic observed in Hurricane Irma’s evacuation periods (i.e., late August and early September 2017). The study involved simulation in mixed traffic scenarios with 25, 50, 75, and 100 percent of different vehicle technologies, including CAVs or Automated Vehicles (AVs) and Human-Driven Vehicles (HDVs).
METHODOLOGY
The study used the microscopic traffic simulation model of a 9.5-mile segment of interstate-75 with two entries and two exit ramps between Gainesville and Ocala in Florida, which was used as an evacuation route during Hurricane Irma in 2017. The study assessed the traffic safety aspects during hurricane evacuation, along with average traffic flow and travel time for the selected roadway. Adaptive cruise control (ACC) was used to represent AV behavior, and the co-simulation was used to mimic CAV behavior. The study used Time-to-collision (TTC), the estimated time for two vehicles to collide if they maintain their current speed and trajectory, as a surrogate safety measure.
FINDINGS
The simulation results found that with 25 percent CAV penetration rate, potential traffic conflicts decreased by 42.5 percent. However, the reduction in potential conflicts was not linear with the increased CAV penetration rate, as the benefit with 50 percent CAV was 56 percent conflict reduction, while 75 percent CAV led to a 53 percent conflict reduction.
A slight decrease in traffic flow was observed across all scenarios, with the highest reduction (2.8 percent) at 25 percent CAV.
