Exploring the effects of Connected and Autonomous Vehicles on traffic safety and operation at full-cloverleaf interchanges

Abstract

The effects of Connected and Autonomous Vehicles (CAVs) on interchanges such as full-cloverleaf interchanges have not yet been examined in prior studies. This study aims to explore the impacts of CAVs on traffic operation and safety at full-cloverleaf interchanges. It also assesses the influence of various Market Penetration Rates (MPRs) of CAVs on travel time, queues lengths, and conflict points considering various weaving lengths using VISSIM. The model calibration and validation were conducted considering different measures of effectiveness (throughput, speed, and travel time). The finding showed that higher MPRs of CAVs led to consistent travel time reductions across on-ramps, off-ramps, and weaving segments. Specifically, moving from the base scenario to 100% MPRs, travel times decreased by 46%, 41%, and 32% at the three interchanges under investigation, respectively. Additionally, safety evaluations utilizing the Surrogate Safety Assessment Model demonstrated considerable declines in the numbers of vehicle conflicts with increases in MPRs, averaging reductions of 20%, 32%, and 26% at the three interchanges from the base scenario to full MPRs, respectively. Also, it was found that increasing the weaving lengths enhanced traffic operation and safety. Overall, the findings highlight the promising benefits of integrating CAVs into the transportation system at full-cloverleaf interchanges.

Keywords:

• Connected and Autonomous Vehicles (CAVs)
• cloverleaf interchanges
• VISSIM
• Traffic safety
• Surrogate Safety Assessment Model (SSAM)

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors received the financial support from Louisiana Transport Research Center (LTRC) (Project number: 23-1SS).