A Max Pressure Algorithm for Traffic Signals Considering Pedestrian Queues

TL;DR

This paper introduces a max-pressure traffic signal control algorithm that integrates pedestrian queues, improving overall efficiency and reducing delays for both vehicles and pedestrians compared to existing methods.

Contribution

It develops a novel max-pressure algorithm that incorporates pedestrian queues into traffic control, maintaining stability and enhancing operational efficiency.

Findings

Reduces person travel delays under various demand levels.

Maintains maximum stability for both vehicles and pedestrians.

Outperforms existing queue-based and rule-based algorithms in simulations.

Abstract

This paper proposes a novel max-pressure (MP) algorithm that incorporates pedestrian traffic into the MP control architecture. Pedestrians are modeled as being included in one of two groups: those walking on sidewalks and those queued at intersections waiting to cross. Traffic dynamics models for both groups are developed. Under the proposed control policy, the signal timings are determined based on the queue length of both vehicles and pedestrians waiting to cross the intersection. The proposed algorithm maintains the decentralized control structure, and the paper proves that it also exhibits the maximum stability property for both vehicles and pedestrians. Microscopic traffic simulation results demonstrate that the proposed model can improve the overall operational efficiency -- i.e., reduce person travel delays -- under various vehicle demand levels compared to the original queue-based MP (Q-MP) algorithm and a recently developed rule-based MP algorithm considering pedestrians. The Q-MP ignores the yielding behavior of right-turn vehicles to conflicting pedestrian movements, which leads to high delay for vehicles. On the other hand, the delay incurred by pedestrians is high from the rule-based model since it imposes large waiting time tolerance to guarantee the operational efficiency of vehicles. The proposed algorithm outperforms both models since the states of both vehicles and pedestrians are taken into consideration to determine signal timings.