A Simulation Framework for Exploring the Impacts of Vehicle Platoons on Mixed Traffic under Connected and Autonomous Environment

Vehicle platooning, first studied as an application of Intelligent Transportation Systems (ITS), is increasingly gaining attention in recent years as autonomous driving and connected vehicle technologies advance. When platooned, vehicles communicate within the platoon and operate with coordination to maintain a relatively steady state status with each other and with the outside. The major goal of this study is to build a conceptual simulation framework to help with exploring the impacts of connected and autonomous vehicle platoons on the existing traffic. The first part of this work effort is reviewing autonomous and connected vehicle technologies for depicting the functional structure of a platooning-ready connected and autonomous vehicle (CAV) platform. Then models and simulation tools are reviewed to break down the simulation framework into two levels—vehicle level and traffic level. The vehicle-level model provides in-depth modeling of CAVs and platooning modules. The traffic-level simulator provides the simulation of the existing traffic with the built CAV platoons. The simulation framework has been developed by integration and usage of GIS, MATLAB/Simulink, SUMO, and OMNeT++. GIS tools are used to gather the necessary traffic data. MATLAB/Simulink serves as the platform for vehicle-level modeling and simulation. SUMO and OMNeT++ are used to build traffic and communication simulations, respectively. The completed model was used to conduct two case studies based on a section of the US Interstate Highway to explore the impacts of CAV platoons on existing traffic. The results indicate that, with the existing traffic pattern and infrastructure design, traffic can be improved after the introduction of CAV platoons, even after taking into consideration the rate of traffic growth. Moreover, deploying dedicated lanes and separating CAV platoon traffic from the non-platooning traffic can benefit the traffic using such output as the travel speed/time and delay measures. However, using such new traffic patterns and infrastructure designs is not recommended for a low percentage of CAV platoon traffic.