An assessment of the accuracy of models in predicting railway traffic flows: a before and after study in NaplesThe Sustainable City IX

摘要

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.