Comparing Lazy Constraint Selection Strategies in Train Routing with Moving Block Control

TL;DR

This paper evaluates different lazy constraint strategies for train routing with moving block control, providing an open-source implementation and benchmarks to optimize capacity and efficiency in rail transportation.

Contribution

It introduces an extended approach and flexible open-source toolkit for lazy constraint strategies in train routing with moving blocks, filling a research gap.

Findings

Different lazy constraint strategies impact routing efficiency

Open-source toolkit enables reproducible evaluations

Benchmark results guide strategy selection

Abstract

Railroad transportation plays a vital role in the future of sustainable mobility. Besides building new infrastructure, capacity can be improved by modern train control systems, e.g., based on moving blocks. At the same time, there is only limited work on how to optimally route trains using the potential gained by these systems. Recently, an initial approach for train routing with moving block control has been proposed to address this demand. However, detailed evaluations on so-called lazy constraints are missing, and no publicly available implementation exists. In this work, we close this gap by providing an extended approach as well as a flexible open-source implementation that can use different solving strategies. Using that, we experimentally evaluate what choices should be made when implementing a lazy constraint approach. The corresponding implementation and benchmarks are publicly available as part of the Munich Train Control Toolkit (MTCT) at https://github.com/cda-tum/mtct.