Evaluation of the Operational Effects of Autonomous and Connected Vehicles through Microsimulation

Proper evaluation of traffic operations integrating connected and autonomous vehicles (CAVs) requires accurate representation of these emerging technologies in microscopic simulation. This paper evaluates the ability of microscopic simulator PTV-VISSIM (Version 10.0) to simulate CAVs, and presents a comprehensive CAV model extension. In addition, emissions modeling is integrated with VISSIM to calculate real-time energy and emission estimates. The evaluation of VISSIM revealed that its internal CAV modeling has several limitations, such as modeling connectivity and complex vehicle behavior. For external modeling, there are two available VISSIM interfaces. The Component Object Model (COM) Application Programming Interface (API) is the superior approach for fetching data and modeling connectivity, whereas the External Driver Model (EDM) is a better tool for lateral and longitudinal control. The simulation extension developed leveraged both interfaces. An isolated signalized intersection was simulated to demonstrate the impact of connected vehicle (CV), autonomous vehicle (AV), and CAV traffic on speed, delay, and travel time. In addition, trajectory data, combined with the Motor Vehicle Emission Simulator (MOVES) method, were utilized to obtain energy, fuel consumption, and greenhouse gas emissions. The results show that CAVs result in net improvement in travel time and speed. However, emissions did not follow the same trend. While increasing AV penetration rates resulted in emissions reductions, increasing CV and CAV penetration rates resulted in higher emissions. While the CV logic chosen for testing seeks to maximize the likelihood of vehicle arrival-on-green, the algorithm likely results in increased variations in second-by-second accelerations, leading to overall higher emissions.

Automated summary

This paper evaluates the ability of microscopic simulator PTV-VISSIM to simulate connected and autonomous vehicles (CAVs) in traffic operations. It also presents a comprehensive CAV model extension and integrates emissions modeling to calculate real-time energy and emission estimates. The evaluation reveals limitations in the internal CAV modeling of VISSIM, but identifies two available interfaces for external modeling. A signalized intersection is simulated to demonstrate the impact of CV, AV, and CAV traffic on speed, delay, and travel time. The results show that CAVs improve travel time and speed, but have mixed effects on emissions.