Reducing selfish routing inefficiencies using traffic lights

TL;DR

This paper introduces a model incorporating traffic lights into congestion games, demonstrating through simulation that appropriate traffic light cycles can reduce the inefficiencies caused by selfish routing and mitigate Braess' paradox effects.

Contribution

The paper presents a novel approach to include traffic lights in congestion models, showing how they can improve route efficiency and reduce paradoxical traffic flow issues.

Findings

Traffic lights influence driver route choices based on red light duration.

Proper traffic light cycle allocation can prevent Braess' paradox.

Simulation results show significant reduction in congestion inefficiencies.

Abstract

Traffic congestion games abstract away from the costs of junctions in transport networks, yet, in urban environments, these often impact journey times significantly. In this paper we equip congestion games with traffic lights, modelled as junction-based waiting cycles, therefore enabling more realistic route planning strategies. Using the SUMO simulator, we show that our modelling choices coincide with realistic routing behaviours, in particular, that drivers' decisions about route choices are based on the proportion of red light time for their direction of travel. Drawing upon the experimental results, we show that the effects of the notorious Braess' paradox can be avoided in theory and significantly reduced in practice, by allocating the appropriate traffic light cycles along a transport network.