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arXiv · 2604.23748

Enforcing TSP-Optimality in Fair Vehicle Routing by Cutting Planes

Bart van Rossum·Rui Chen·Andrea Lodi
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Abstract

We study the fair capacitated vehicle routing problem, in which a fleet of vehicles must serve a set of customers such that the difference between the longest and shortest route, the range, is minimized. A key challenge is that the range objective is non-monotonic: it can be reduced by artificially lengthening routes, leading to solutions that violate TSP-optimality of individual routes. Existing exact methods struggle to handle this efficiently. We propose a branch-price-and-cut framework that enforces TSP-optimality through TSP-optimality cuts, which forbid TSP-dominated arc sequences. We strengthen the cuts through a dedicated lifting procedure. Computational experiments on benchmark instances with up to 25 customers show the method solves nearly all instances to optimality, achieving an average gap of 0.27% on the hardest configurations.

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Bart van Rossum, Rui Chen, Andrea Lodi. 2026-04-26. Enforcing TSP-Optimality in Fair Vehicle Routing by Cutting Planes. https://arxiv.org/abs/2604.23748

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