Code and experiments of the paper "A model for pricing freight rail transport access costs: economic and environmental perspectives"

Authors:

• Ricardo García-Ródenas
• Esteve Codina
• Luis Cadarso
• María Luz López-García
• José Ángel Martín-Baos

These codes are associated with the paper "A model for pricing freight rail transport access costs: economic and environmental perspectives"

If you use any part of the code or data provided in this repository, please cite it as:

Ricardo García-Ródenas, Esteve Codina, Luis Cadarso, María Luz López-García, José Ángel Martín-Baos "A model for pricing freight rail transport access costs: economic and environmental perspectives". arXiv preprint. DOI: 10.48550/arXiv.2504.04257

You can also access the preprint version of this paper on arXiv.

Abstract

In deregulated railway markets, efficient management of infrastructure costs is essential for sustaining railway systems. This study presents a method for infrastructure managers to price access to railway infrastructure, focusing on freight transport in deregulated market contexts. The proposed methodology innovatively incorporates negative externalities directly into the pricing structure, balancing economic and environmental objectives. A dynamic freight flow model is developed to represent the railway system, using a logit model to capture the modal split between rail and road based on costs, thereby reflecting demand elasticity. The model is temporally discretized, resulting in a mesoscopic, discrete-event simulation framework, which is integrated into an optimization model that calculates train path rates based on real-time capacity and demand, aiming both to maximize revenue for the infrastructure manager and reduce the negative externalities of road transport. The methodology is demonstrated through a case study on the Mediterranean Rail Freight Corridor, showcasing the scale of access charges derived from the model. Results indicate that reducing track access charges can yield substantial societal benefits by shifting demand to rail. This research provides a valuable framework for transport policy, suggesting that externality-sensitive tariffs can promote more efficient and sustainable use of railway infrastructure.

Software implementation

All source code used to generate the results and figures in the paper are contained in this repository. The code is written in MATLAB, and is organised in the following folders:

The data used in this study is provided in the DATA folder. In this subdirectory, you will find the data used to construct the case study for the Mediterranean Corridor. The file TopologyMediterraneanCorridor.xlsx contains all the data used in its development. The resulting case study is stored in the file MC.mat.

The RESULTS folder contains the various data obtained from the scenario simulations (Matlab files with the extension .mat) and the preparation of the results (files with the extension .tex).

Files

The purpose of the various .m files developed is described below:

0. MainTopology.m: generates the case study for the Mediterranean Corridor. After execution, it creates a MATLAB file MC.mat that stores the structure (data type) MC and the graph G containing all the necessary information. Running in the prompt >> exploreStruct(MC,[]) displays all the fields of the structure MC.

1. • ObjectiveFunction.m: Defines the objective function using the discrete event simulation model. The model is parametrised by Track Access Charges It also utilizes the auxiliary functions CapacityDynamic.m and Logit_r.m

   • mainOptimization.m script performs the optimization process for the defined objective function and saves the results. Users can select scenarios 1, 2, or 3 from the paper or define a new one, and choose from optimization algorithms like {'active-set','interior-point','sqp','pso','ga','patternsearch'}

2. • MainExperiment1.m: processes the experimental data corresponding to the section “Results I: Establishing Charges from the IM’s Perspective” in the paper. The script mainOptimization.m generates the input ['./RESULTS/experiment1_' NameModel '.mat'] for this script

   • MainExperiment2.m: processes the experimental data corresponding to the section “Results II: Establishing the Pricing Method from the State’s Perspective” in the paper.

Dependencies

Function table2latex(T, filename) converts a given MATLAB(R) table into  a plain .tex file with LaTeX formatting.  This function is required in MainExperiment1.m and MainExperiment2.m. 
The author of this function is Victor Martinez Cagigal.

Bug reports and feature requests

If you encounter any issues or have ideas, you can contact us at ricardo.garcia@uclm.es.

Getting the code

You can download a copy of all the files in this repository by cloning the git repository:

git clone https://github.com/RicardoGarciaRodenas/TAC-access-charge-for-freight-rail-transport.git

or download a zip archive.

License

All source code is made available under a MIT license. You can freely use and modify the code, without warranty, so long as you provide attribution to the authors. See LICENSE.md for the full license text.

The manuscript text is not open source. The authors reserve the rights to the article content, which is currently submitted for publication in Transportation Research Part B: Methodological.