Differences between the traffic model and the actual road traffic and its structure

Abstract

The paper presents two models of traffic forecasting developed for two completed road construction projects in two cities of Poland: Lublin and Poznan. The predictions from both models were compared with the field data. In the first part the article presents the currently used model for computational determination of road projects’ viability, including indication of relationships between road traffic forecasts on the one hand and actual road operations and viability of road projects on the other. The second part presents results of various international studies on road projects in order to show the differences between the predicted and the actual traffic volumes, which is typical for most developed countries. Then, the article discusses the differences observed between the model outputs and the actual traffic and its structure in the analysed road projects. Finally, the authors put forward their conclusions regarding the inconsistencies between the traffic models (as well as the resulting traffic forecasts) and the actual transport performance.