Simulation-based Analysis of a Novel Loop-based Road Topology for Autonomous Vehicles

TL;DR

The paper investigates a novel Zonal Road Topology, consisting of unidirectional loops and crossovers without traditional traffic signals, as a potential enabler for safer, more energy-efficient autonomous driving. Using a simulation-based framework that combines SUMO for traffic, a Simulink EV model for energy, and MATLAB scripts for metrics, the authors compare the Zonal topology to traditional signalized layouts on a 10×10 grid under varied traffic levels. Results show that Zonal routing yields lower drive-time variability, higher throughput, and lower energy use at higher densities, despite longer travel distances. The study demonstrates the topology’s promise toward continuously flowing smart cities and L4/L5 autonomy, while acknowledging the need for further research, policy alignment, and multi-disciplinary collaboration for real-world deployment.

Abstract

The challenges in implementing SAE Level 4/5 autonomous vehicles are manifold, with intersection navigation being a pervasive one. We analyze a novel road topology invented by a co-author of this paper, Xiayong Hu. The topology eliminates the need for traditional traffic control and cross-traffic at intersections, potentially improving the safety of autonomous driving systems. The topology, herein called the Zonal Road Topology, consists of unidirectional loops of road with traffic flowing either clockwise or counter-clockwise. Adjacent loops are directionally aligned with one another, allowing vehicles to transfer from one loop to another through a simple lane change. To evaluate the Zonal Road Topology, a one km2 pilot-track near Changshu, China is currently being set aside for testing. In parallel, traffic simulations are being performed. To this end, we conduct a simulation-based comparison between the Zonal Road Topology and a traditional road topology for a generic Electric Vehicle (EV) using the Simulation for Urban MObility (SUMO) platform and MATLAB/Simulink. We analyze the topologies in terms of their travel efficiency, safety, energy usage, and capacity. Drive time, number of halts, progress rate, and other metrics are analyzed across varied traffic levels to investigate the advantages and disadvantages of the Zonal Road Topology. Our results indicate that vehicles on the Zonal Road Topology have a lower, more consistent drive time with greater traffic throughput, while using less energy on average. These results become more prominent at higher traffic densities.

Figures (11)

• Figure 1: Sample vehicle route in the Zonal Road Topology on a small grid.
• Figure 2: Types of vehicular conflicts present in traditional cross-intersections, roundabouts, and the Zonal Road Topology.
• Figure 3: Zonal Road Topology with a different configuration of clockwise (orange) and counter-clockwise (green) loops.
• Figure 4: Simulation pipeline used to run all the simulations in this paper.
• Figure 5: Zipper merges within the Zonal Road Topology, highlighted in blue.