An assessment of the accuracy of models in predicting railway traffic flows: a before and after study in Naples

Abstract

The relevant interactions among the various elements of a transportation system can be simulated with mathematical models. In literature there is a great number of applications of these models. They are generally estimated so as to reproduce the observed actual system conditions and then applied to predict the future system conditions due to possible changes in the supply system. But what is the reliability of these predictions? Very few studies have been conducted in order to verify the reliability of these models by comparing the real future system conditions with those predicted by the model. Starting from these considerations, this paper investigates the prediction reliability of the transport system models, developed for the Campania (Italy) Regional Metro System (RMS), through a before and after study, taking advantage of the opening of new parts of railways system occurred over the last twenty years. Some interesting remarks can be made from the results analysis allowing to avoid unreal demand estimations. For example, a correction procedure of transport model system based on aggregate data (traffic counts) seems to be necessary to obtain a model with an acceptable capability to reproduce/forecast transport systems. Otherwise, when dealing with considerable changes in the supply system (for example the opening of new metro lines), considerable changes in the OD demand might also be expected and, therefore, a model is absolutely needed to forecast these changes.

A new look at planning and designing transportation systems: A decision-making model based on cognitive rationality, stakeholder engagement and quantitative methods

“…In this framework, project impacts on both mobility and transport networks were forecast using a system of mathematical models including travel demand models, public and private networks models, assignment and impact simulation models Bifulco et al, 2010;Cartenì et al, 2010).…”

Congested Urban Areas with High Interactions Between Vehicular and Pedestrian Flows: A Cost-Benefit Analysis for a Sustainable Transport Policy in Naples, Italy

“…The model has also allowed to calculate all the synthetic indicators useful to evaluate the proposed design scenario and eventually integrate and/or modify them. The macroscopic simulation model was composed by a within-day static models with variable demand (for details see also [12,13]:…”

A Sustainable Evaluation Processes for Investments in the Transport Sector: A Combined Multi-Criteria and Cost–Benefit Analysis for a New Highway in Italy

“…Definitely, the multi-criteria analysis generally allows a more reliable estimation of the non-users' impacts [78][79][80][81][82][83][84] (e.g., non-monetary externalities such as greenhouse gas emissions, naturalistic impacts, aesthetic quality) that are generally underestimated with cost-benefit analysis. On the other hand, cost-benefit analysis is a more standardized and less discretionary procedure (e.g., application of the national and/or the EU guidelines [85,86]) and it is commonly considered a "solid" evaluation method to reduce the risk of planning fallacy and minimize conflicts over decisions (enlarges the consensus).…”