A Simulation Model for Strategies of Vehicle Weight Regulation Using System Dynamics

Highway freight transportation system is an exoteric gigantic system with high-steps, multi-variables, multi-loops and nonlinear feedback structure. In order to make evaluation on social impacts of truck overloading transportation, a methodological framework with a integrated system dynamics (SD) model which includes freight demand sub-model, vehicle usage sub-model, vehicle operating cost sub-model, vehicle evolvement sub-model and road performance sub-model, is established. As an application in Anhui, long-term performance of highway freight transportation system under different vehicle weight limit strategies are analyzed using the new-developed model. The evaluation results show that the highway freight system has poor sensitivity to fuel price, pavement thickness, pavement maintain interval and road user tax in the situation of ubiquitous overloading tracks. Thereby, a set of moderate vehicle weight limits are necessary to be introduced.