Transactions on Transport Sciences

Transactions on Transport Sciences X:X

Can Autonomous Vehicles Improve the Traffic Flow Efficiency in Heterogeneous Traffic Environments? A Simulation-based Investigation

Mithun Mohan^a, Kiran Gopal^b

^a. Assistant Professor (corresponding author), Department of Civil Engineering, National Institute of Technology Karnataka, Surathkal, Mangalore, India - 575025. Email: mithun@nitk.edu.in

^b. MTech Student

Autonomous vehicles promise numerous benefits for future mobility, including reduced stress for drivers, congestion, emissions, and energy consumption, as well as increased safety, road capacity, and efficient parking management. A detailed literature review revealed the scarcity of research on connected and autonomous vehicles in developing countries. The present study employs microscopic simulation to analyse the impact of autonomous vehicle penetration in the mixed driving environment prevalent in India. The simulation was carried out by modelling a typical autonomous vehicle (AV) and introducing it to various parts of a road network, including midblock sections of highways and expressways, signalised and unsignalized intersections, and allowing it to operate along with conventional vehicles. The parameters in VISSIM were adjusted to closely mimic the Indian traffic operations. Simulation results indicated that uninterrupted facilities of highway and expressway midblock sections showed an improvement in throughput with the penetration of AV into the conventional stream of vehicles. While the capacity of the expressway increased by almost 87%, the increase was by 21% for the highway sections. At the same time, the penetration of AVs into facilities with interrupted traffic, such as signalised and unsignalized at-grade intersections, decreased the traffic throughput. While the reduction in capacity was marginal for signalised intersections (1.3%), there was a significant reduction for unsignalized intersections (13-18%). The drop in capacity at interrupted facilities could be attributed to the cautious nature of AVs in comparison to conventional traffic.

Keywords: Autonomous Vehicles; Heterogeneous Traffic; Intersections; Midblock Sections; VISSIM

Received: August 4, 2025; Revised: December 18, 2025; Accepted: January 16, 2026; Prepublished online: August 28, 2026