Network Navigation with Online Delays is PSPACE-complete

TL;DR

This paper models public transport delays as a game between a traveler and an adversary, proving that deciding the traveler's ability to reach a destination despite delays is PSPACE-complete, highlighting computational complexity challenges.

Contribution

It introduces a formal game-theoretic model for resilience in public transport networks and establishes the PSPACE-completeness of the decision problem.

Findings

Deciding the traveler's winning strategy is PSPACE-complete.

The problem models delays as an adversarial game.

Complexity results inform resilience analysis in transport networks.

Abstract

In public transport networks disruptions may occur and lead to travel delays. It is thus interesting to determine whether a traveler can be resilient to delays that occur unexpectedly, ensuring that they can reach their destination in time regardless. We model this as a game between the traveler and a delay-introducing adversary. We study the computational complexity of the problem of deciding whether the traveler has a winning strategy in this game. Our main result is that this problem is PSPACE-complete.