Joaquin Rodriguez

• Gustave Eiffel University

This paper addresses the real-time Railway Traffic Management Problem (rtRTMP), which involves adjusting train timetables during perturbations. Perturbations in railway networks often lead to significant delays, necessitating strategies to minimize their propagation. An important objective of traffic management is to facilitate passenger transfers...

Railway operations are highly susceptible to delays and disruptions caused by various factors, such as technical issues, operational inefficiencies, and unforeseen events. To counter these delays and ensure efficient railway operations during real-time management, several rescheduling approaches can be implemented. Among these approaches, passenger...

To ensure a safe and regular train service, rail infrastructure managers periodically and with large advance design timetables. However, train schedules and operations are subordinated to a large number of parameters, making them vulnerable to service disturbances. The dispatchers are thus required to quickly detect new conflicts arising during ope...

Strategic planning is critical in helping railways develop optimal programs for improving their business by making service more attractive and efficient. Preparing a strategic plan requires comparing multiple alternatives and options, each requiring time-consuming planning, evaluation, and analysis. To improve this process Jernbanedirektoratet, Nor...

This paper treats theoretical and practical aspects of train management in freight shunting yards. It is a literature survey extending the previous ones and presenting the new important papers published in the last decade. The operations realised in such yards are formalised by modelling them in unified modelling language diagrams and the algorithm...

The real-time Railway Traffic Management Problem (rtRTMP) is the problem of detecting and solving time-overlapping conflicting requests made by multiple trains on the same track resources. This problem consists in retiming, reordering and rerouting trains in such a way that the propagation of disturbances in the railway network is minimized. The rt...

In railway traffic, perturbations may give rise to conflicts, causing delays. As a countermeasure, effective re-scheduling and rerouting decisions can be taken by addressing the real-time Rail Traffic Management Problem (rtRTMP). One of its subproblems is the real-time Energy Consumption Minimization Problem (rtECMP). The latter enforces the train...

The real-time Train Routing Selection Problem (rtTRSP) is the combinatorial optimization problem of selecting, for each train in a rail network, the best routing alternatives. Solving the rtTRSP aims to limit the search space of train rescheduling problems, highly affected by the number of routing variables. The rtTRSP is modelled as the minimum we...

This paper proposes different algorithms to tackle the Generalized Train Unit Shunting Problem (G-TUSP). This is the pre-operational problem of managing rolling stock in a station, between arrivals and departures. It includes four sub-problems: the Train Matching Problem, the Track Assignment Problem, the Shunting Routing Problem, and the Shunting...

The real-time Railway Traffic Management Problem (rtRTMP) is the problem of detecting and solving time-overlapping conflicting request done by multiple trains on the same track resources. It typically consists in taking retiming, reordering or rerouting train actions in such a way that the propagation of disturbances in the railway network is minim...

Les temps de stationnement en gare en Île-de-France peuvent avoir un impact significatif sur la régularité des trains transilien. L'optimisation des durées de stationnement est essentielle pour une exploitation efficace, en n'étant ni trop courtes, ni trop longues. Le déploiement d'un système de comptage automatique des voyageurs emb...

In railway systems, during congested traffic situations, the infrastructure capacity is completely exploited for trains circulation. When traffic is perturbed, some trains must be stopped or slowed down for ensuring safety, and delays occur. The real-time Railway Traffic Management Problem (rtRTMP) is the problem of modifying trains route and sched...

Railway operations in dense traffic areas are very sensitive even to small disturbances, and thus require careful planning and real-time management. Dwell times in stations are in particular subject to a high variability and are hard to predict; this is mostly due to the interactions between passengers and the railway system during the dwelling pro...

The real-time Railway Traffic Management problem consists in finding suitable train routes and schedules to minimize delay propagation due to traffic perturbations. RECIFE-MILP is a mixed integer linear programming based heuristic for this problem which has proven to be effective in various contexts. However, when instances are very large or diffic...

The efficiency of rail good transportation is dependent on the processes implemented in shunting yards. Specifically, from the network, trains arrive and depart through the receiving and the departure bowl, respectively. The railcars of the inbound trains are recombined to form the desired outbound trains with the use of a hump from where they slid...

In order to achieve higher capacity on existing infrastructures with dense traffic, railway companies are deploying Communication Based Train Control (CBTC) systems. These systems would considerably facilitate the implementation of new ways for managing traffic, such as headway-based control. However, for commercial reasons, traffic management syst...

Maintenance activities on the railway infrastructure are necessary to maintain its functionality and availability. Commonly, the maintenance activities are planned first. Then, the timetable is elaborated respecting the unavailability periods caused by the former. However, sometimes unplanned maintenance activities have to be introduced at short no...

In this paper we propose a reformulation of RECIFE-MILP aimed at boosting the algorithm performance. RECIFE-MILP is a mixed integer linear programming based heuristic for the real-time railway traffic management problem, that is the problem of re-routing and rescheduling trains in case of perturbation in order to minimize the delay propagation. The...

Measuring capacity of railway infrastructures is a problem even in its definition. In this paper, we propose RECIFE-SAT, a MILP-based algorithm to quantify capacity by solving the saturation problem. This problem consists of saturating an infrastructure by adding as many trains as possible to an existing (possibly empty) timetable. Specifically, RE...

Mots-clés : real-time railway traffic management problem, MILP, Benders algorithm. For many railway systems, during rush hours, the infrastructure capacity is completely exploited for ensuring the trains circulation. Many trains travel within short time through critical points. If a disturbance occurs, the traffic may be perturbed and, as a result,...

In the real-time railway traffic management problem, the number of alternative routings available to each train strongly affects the size of the problem and the time required to optimally solve it. The train routing selection problem identifies a suitable subset of alternative routings to be used for each train in the real-time railway traffic mana...

The real-time railway traffic management problem is the problem of solving time-overlapping conflicting track requests generated by disturbances during the normal course of daily operations. The size of an instance of the problem and the time required to solve it are particularly affected by the number of routing alternatives available to each trai...

Railway traffic is often perturbed by unexpected events. To effectively cope with these events, the real-time railway traffic management problem (rtRTMP) seeks for train routings and scheduling which minimizes delay propagation. The size of rtRTMP instances is strongly affected by the number of routing alternatives available to each train. Performi...

Maintenance activities are necessary to maintain the functionality of the railway infrastructure. Commonly, the maintenance activities are planned first. Then, the timetable is elaborated respecting the unavailability periods caused by the former. However, unplanned maintenance activities may have to be introduced at short notice, and the timetable...

In railway planning, the timetabling step needs, as input, the train running times, which are calculated from a train dynamic model. Usually, this model determines the most energy-efficient train trajectory for a predefined time. However, this time may not correspond to the timetable-makers' needs. They should have the choice among a set of solutio...

In railway traffic, at peak hours, the infrastructure is extensively exploited for ensuring the trains circulation. It means that many trains travel within short time through critical points. If a disruption occurs, the traffic may be perturbed and, as a result, conflicts may emerge. In a conflict, multiple trains may claim the same track section c...

Automatic real-time control of traffic perturbations has recently become a central issue for many European railway infrastructure managers. The aim is to make use of mathematical algorithms to maintain the required service availability during unplanned disturbances to operations. In the literature many tools for real-time traffic control are propos...

This paper deals with the real-time problem of scheduling and routing trains in a railway network. In the related literature, this problem is usually solved starting from a subset of routing alternatives and computing the near-optimal solution of the simplified routing problem. We study how to select the best subset of routing alternatives for each...

Railway traffic is often perturbed by unexpected events causing delays, which may greatly propagate. Nowadays, dispatchers deal with delays trying to limit this propagation with scarce decision support tools. RECIFE-MILP is an optimization algorithm which may be used to support dispatchers' decisions. In this paper, we illustrate the analysis perfo...

The growth in transport demand of the last years is a trend expected to continue in the coming years. In railways, the difficulties in building new infrastructures due to high costs or physical obstacles have translated into the need to utilize the already existing infrastructures at their full capacity. During the daily operations disturbances may...

The real-time railway traffic management problem consists of selecting appropriate train routes and schedules for minimizing the propagation of delay in case of traffic perturbation. In this paper, we tackle this problem by introducing RECIFE-MILP, a heuristic algorithm based on a mixed-integer linear programming model. RECIFE-MILP uses a model tha...

Railway traffic is often perturbed by unexpected events and appropriate train routing and scheduling shall be applied to minimize delay propagation. A number algorithms for this routing and scheduling problem have been proposed in the literature and they have been tested in different traffic situations. Nonetheless, their performance are almost alw...

Transilien, the SNCF branch in charge of operating the main urban railroad network in the area of Paris, faces a regular increase of passenger flows. The planning of railway operations is made carefully through simulation runs which help to assess the timetable stability. However, many disturbances appear and cause train delays. Due to the nature o...

Railway operation management must cope with failures of the railway system or external disturbances that may cause initial delays or so-called primary delays. In heavy traffic areas of rail networks, primary delays can quickly propagate and lead to the so-called secondary or knock-on delays. This paper describes the results of experiments done to e...

In railway operations, a timetable is established to determine the departure and arrival times for the trains or other rolling stock at the different stations or relevant points inside the rail network or a subset of this network. The elaboration of this timetable is done to respond to the commercial requirements for both passenger and freight traf...

Railway operations management must cope with system failures and external disturbances that may cause delays. In heavy traffic areas, these delays can quickly propagate. This study details the results of a railway traffic optimization tool based on a MILP formulation. The case studies tackled represent different European locations. These experiment...

We propose an optimal train dispatching module which computes in real-time the train routing and scheduling that minimize delay propagation. For solving this real-time railway traffic management problem, we exploit a fixed-speed mixed-integer linear programming (MILP) formulation (Pellegrini et al., 2014). To take into account the operational const...

La gestion du trafic ferroviaire s’effectue par choix de routage et d'ordonnancement des trains qui minimisent la propagation de retards en cas de perturbation. Dans cet article, nous proposons des inégalités valides et des choix algorithmiques permettant d’améliorer les performances d'une formulation de programmation linéaire en nombres entiers po...

Railway operations management must cope with failures of the railway system and with external disturbances that may cause initial delays, the so-called primary delays. In heavy traffic areas of railway networks, primary delays can quickly lead to many further delays, called secondary delays or knock-on delays. This paper describes the results of an...

Real-time traffic management in railway aims to minimize delays after an unexpected event perturbs the operations. It can be formalized as the real-time railway traffic management problem, which seeks for the best train routing and scheduling in case of perturbation, in a given time horizon. We propose a mixed-integer linear programming formulation...

Unexpected events often perturb railway traffic. The impact of these events may be very remarkable in terms of delay propagation. We analyze a mixed integer linear programming (MILP) formulation which aims at minimizing the delay propagation when traffic is perturbed. It does so by modifying train routing and scheduling at junctions. This formulati...

The timetabling step in railway planning is based on the estimation of the running times. Usually, they are estimated as the shortest running time increased of a short time supplement. Estimating the running time amounts to define the speed profile which indicates the speed that the train driver must hold at each position. The approach proposed in...

Air and rail transportation systems are characterized by important common features: they serve a significant share of passenger traffic in Europe; their functioning relies on the cooperation of many stakeholders operating a fixed timetable, often with competing objectives; and they have been characterized by quite a fragmented development following...

In train operations, a timetable is used to establish the departure and arrival times for the trains at the stations or other relevant locations in the rail network or a subset of this network. The elaboration of a timetable responds to the commercial needs of the customers, for both passenger and freight traffic, but also, it must respect some sec...

In railway traffic management, when an unexpected event perturbs the system, finding an effective train routing and scheduling in real-time is a key issues. Making the right routing and scheduling decisions may have a great impact on the efficiency of the system in terms of delay propagation. However, the time available for making these decisions i...

Rail traffic management consists in optimizing perturbed traffic selecting train routing and scheduling. In this study, we propose different sets of valid inequalities for boosting the performance of a MILP formulation in terms of computation time. We apply an automatic algorithm configuration procedure for selecting both the appropriate sets of in...

In railway timetabling, the train running times are often known as the shortest durations between two stations increased of some percent of time. The running times are estimated by constructing the speed profiles that the trains must hold along the track. In this paper, an approach is proposed to compute several speed profiles for a same travel. Th...

In this paper, we propose a mixed-integer linear programming formulation for tackling a classic problem in railway traffic management. In particular, we deal with perturbed traffic in a complex junction. Here, multiple lines cross allowing train routing and scheduling modifications with respect to the planned timetable. Our formulation exploits alt...

L’une des problématiques actuelles du domaine ferroviaire est de minimiser la consommation énergétique sur le réseau sans impacter plus que nécessaire le temps de trajet des trains. Le modèle présenté a pour objectif d’une part, de proposer un ensemble de profils de vitesse étant des compromis entre temps de parcours et consommation énergétique. Et...

At peak hours, railway timetables extensively exploit the infrastructure for accommodating traffic. Hence, the occurrence of unexpected events, even of apparently negligible entity, may cause a relevant deviation with respect to the scheduled timetable. If a train is delayed due to an unexpected event, conflicts may emerge, multiple trains may clai...

In this paper, an approach for speed tuning in railway management is proposed in order to optimize journey duration and energy consumption. Indeed, in railway transportation, fastness of travel has often been preferred to other criteria, such as energy. However, for recent years, the concern due to pollution and global warming leads to develop more...

The real time railway traffic management seeks for the train routing and scheduling that minimize delays after an unexpected event perturbs the operations. In this paper, we propose a mixed-integer linear programming formulation for tackling this problem, modeling the infrastructure in terms of track-circuits, which are the basic components for tra...

Scheduling theory (ST) is a formal framework which have been used many times over the last decade as starting point to model railway traffic management. Graph theory (GT), mathematical programming (MP) or constraint programming (CP) have also be used as additional steps to scheduling theory. This is illustrated in figure 1. The last step is a solut...

In this paper an approach is proposed for optimization of speed profiles in railway integrating energy saving. This approach deals with a multi-objective problem involving three criteria: reduction of the travel duration, reduction of the delays and minimization of the energy consumption. Based on a state of the art evolutionary algorithm, the prop...

Ce chapitre met l'accent sur la méthode de résolution approchée qui repose sur le paradigme des colonies de fourmis, et qui a été proposée pour la mesure et l'optimisation de la capacité des noeuds ferroviaires ou des gares. Les expérimentations numériques présentées illustrent un ensemble de fonctionnalités faisant usage de cet algorithme en tant...

http://spiderman-2.laas.fr/roadef2010/actes/resumes/p111.pdf

Railway networks are faced to an increase demand of new services. This situation leads to train schedules close to the maximum capacity of the infrastructure. As the extension of the infrastructure is too expensive, an alternative solution is to improve traffic management in congested areas. This task can be formulated as an optimization problem wh...

This research deals with a real-world planning problem in railway infrastructure operations. It is part of the RECIFE project, which seeks to develop a decision support software to help evaluate the capacity of a rail junction or station. To this end, the project is working on a timetable optimization model, as well as timetable evaluation modules....

Ce chapitre met l'accent sur la méthode de résolution approchée qui repose sur le paradigme des colonies de fourmis, et qui a été proposée pour la mesure et l'optimisation de la capacité des noeuds ferroviaires ou des gares. Les expérimentations numériques présentées illustrent un ensemble de fonctionnalités faisant usage de cet algorithme en tant...

In this paper, we present a constraint programming model for the routing and scheduling of trains running through a junction. The model uses input data from relevant time events of train runs calculated by a simulator. The model can be integrated into a decision support system used by operators who make decisions to change train routes or orders to...

We introduce a new proof system for the description logic ALC in the framework of the calculus of structures, a structural proof theory that employs deep inference. This new formal presentation intro- duces positive proofs for description logics. Moreover, this result makes possible the study of sub-structural refinements of description logics, for...

C06-32 - PROJET RECIFE Convention N° 02 31 0045

Model-based diagnosis, and constraint-based reasoning are well known generic paradigms for which the most difficult task lies in the construction of the models used. We consider the problem of localizing and correcting the errors in a model. We present a method to debug a model. To help the debugging task, we propose to use the model-base diagnosis...

http://www.emse.fr/~delorme/Papiers/MIC05/MIC05_resume.pdf

In this article we study the evaluation of the rail-way infrastructure capacity for a node, a station. The prob-lem considered is the saturation problem of a railway infras-tructure. It is modelised in a Satisfaction Constraint Prob-lem (CSP). Some improvements are added to the model such as the reduction of the number of variables, the number of c...

The principles of the Greedy Randomized Adaptative Search Procedure (GRASP) metaheuristic are instantiated for the set packing problem. We investigated several construction phases, and evaluated improvements based on advanced strategies. These improvements include a self-tuning procedure (using reactive GRASP), an intensification procedure (using p...

This research concerns the problem of the evaluation of the railway infrastructure capacity. It is an important question when railway authorities have to choose between different infrastructure investment projects. We developped independently two heuristic approaches to solve the infrastructure saturation problem. The first is based on a constraint...

A lot of work has been made to improve CSP solvers capabilities. Most of the results concern binary CSP. But, it is useful to manipulate n-ary constraints. In this paper, CSP are over constrained and the goal consists in finding origin of this lack of solution or in explaining them. We take the model-based diagnosis as a dynamic CSP to illustrate o...

In this paper we present a rule based formalism for filtering variables domains of constraints. This formalism is well adapted for solving dynamic CSP. We take diagnosis as an instance problem to illustrate the use of these rules. A diagnosis problem is seen like finding all the minimal sets of constraints to be relaxed in the constraint network th...

The progress in telematics at the level of surface public transport resulted in the progressive implementation of centralised fleet management systems based on automatic vehicle monitoring systems (AVM). However faced with the many disturbances on public transport, the operators have much difficulty in detecting situations with problems and make th...

The Elodi project described aims at realizing a framework to produce a maintenance tool (diagnose and repair) of a complex system using the design data. This study is applied to a large scale and complex system: the high speed signalling system TVM 430. Since 1993, this device is used to bring the on-board signalling of the TGV (French high speed t...

This paper shows an implementation of the model-based diagnosis theory. It focuses on the extensions of a constraint based modelling language to describe the temporal behaviour. The resulting diagnosis program is able to reason about time and has been applied to the diagnosis of electronic devices of automated guided transit systems