Dispatching and Rescheduling Tasks and Their Interactions with Travel Demand and the Energy Domain: Models and Algorithms

Abstract The paper aims to provide an overview of the key factors to consider when performing reliable modelling of rail services. Given our underlying belief that to build a robust simulation environment a rail service cannot be considered an isolated system, also the connected systems, which influence and, in turn, are influenced by such services, must be properly modelled. For this purpose, an extensive overview of the rail simulation and optimisation models proposed in the literature is first provided. Rail simulation models are classified according to the level of detail implemented (microscopic, mesoscopic and macroscopic), the variables involved (deterministic and stochastic) and the processing techniques adopted (synchronous and asynchronous). By contrast, within rail optimisation models, both planning (timetabling) and management (rescheduling) phases are discussed. The main issues concerning the interaction of rail services with travel demand flows and the energy domain are also described. Finally, in an attempt to provide a comprehensive framework an overview of the main metaheuristic resolution techniques used in the planning and management phases is shown

Defining Reserve Times for Metro Systems: An Analytical Approach

The aim of this paper is to provide an analytical approach for determining operational parameters for metro systems so as to support the planning and implementation of energy-saving strategies. Indeed, one of the main targets of train operating companies is to identify and implement suitable strategies for reducing energy consumption. For this purpose, researchers and practitioners have developed energy-efficient driving profiles with the aim of optimising train motion. However, as such profiles generally entail an increase in travel times, the operating parameters in the planned timetable need to be appropriately recalibrated. Against this background, this paper develops a suitable methodology for estimating reserve times which represent the main rate of extra time needed to put ecodriving strategies in place. Our proposal is to exploit layover times (i.e., times spent by a train at the terminus waiting for the next trip) for energy-saving purposes, keeping buffer times intact in order to preserve the flexibility and robustness of the timetable in case of delays. In order to show its feasibility, the approach was applied in the case of a real metro context, whose service frequency was duly taken into account. In particular, after stochastic analysis of the parameters involved for calibrating suitable buffer times, different operating schemes were simulated by analysing the relationship between layover times, number of convoys, and feasible headway values. Finally, some operation configurations are analysed in order to quantify the amount of energy that can be saved

Methodology for Determining Dwell Times Consistent with Passenger Flows in the Case of Metro Services

Abstract The importance of a mobility system based on railway technology as the backbone of public transport is now widely acknowledged. Indeed, rail systems are green, high performing, smart and able to ensure a high degree of safety. Therefore, modal split should be steered towards rail transport by increasing the attractiveness of this transport mode. In this context, a key element is represented by the timetabling design phase, which must aim to guarantee an appropriate degree of robustness of rail operations in order to ensure a high degree of system reliability and increase service quality. A crucial factor in the task of timetabling entails evaluating dwell times at stations. The innovative feature of this paper is the analytical definition of dwell times as flow dependent. Our proposal is based on estimating dwell times according to the crowding level at platforms and related interaction between passengers and the rail service in terms of user behaviour when a train arrives. An application in the case of a real metro system is provided in order to show the feasibility of the proposed approach

A methodology for long-term analysis of innovative signalling systems on regional rail lines

A rail system may be considered a useful tool for reducing vehicular flows on a road system (i.e. cars and trucks), especially in high-density contexts such as urban and metropolitan areas where greenhouse gas emissions need to be abated. In particular, since travellers maximise their own utility, variations in mobility choices can be induced only by significantly improving the level-of-service of public transport. Our specific proposal is to identify the economic and environmental effects of implementing an innovative signalling system (which would reduce passenger waiting times) by performing a cost-benefit analysis based on a feasibility threshold approach. Hence, it is necessary to calculate long-term benefits and compare them with intervention costs. In this context, a key factor to be considered is travel demand estimation in current and future conditions. This approach was tested on a regional rail line in southern Italy to show the feasibility and utility of the proposed methodology

Optimization models for the urban park pricing problem

Park pricing strategies are an important tool for rebalancing the modal split between personal car and transit systems in urban area. In fact, the high levels of congestion are mainly due to the preference of users for the private car system. In order to obtain a more equilibrate modal split it is possible, jointly with the improvement of transit system quality, to impose fares on use of private cars; it can be obtained by road pricing and/or park pricing strategies. Park pricing strategies are the simplest ones, since they can be managed without the adoption of advanced technologies.In this paper some park pricing strategies are proposed and some optimization models are formalized; these optimization models search for the optimal parking fares optimizing the value of some objective functions

A multimodal approach for managing transportation design problems of real size networks

Most network design models proposed in the literature analyse only one transportation mode (road or transit systems) and are based on the assumption of rigid modal split. To overcome these limits, the authors propose models and algorithms for solving transportation design problems from a multimodal point of view. The paper also provides two applications of the multimodal approach in the case of fare design