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

TL;DR

This work provides an extended approach as well as a flexible open-source implementation that can use different solving strategies to evaluate what choices should be made when implementing a lazy constraint approach for train routing with moving block control.

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.

Figures (3)

• Figure 1: Schematic drawings of different signaling principles
• Figure 2: Example Setting for Symbolic Formulation
• Figure 3: Runtime of Different Lazy Constraint Strategies

Theorems & Definitions (3)

• Example 2.1
• Example 2.2
• Example 4.1