A Study On Strategies Of Weight Regulation For Highway Freight Vehicles

It is well known that highway freight transportation is of great importance to social economy activities and vehicle weight regulation (VWR) has tremendous impacts on highway freight efficiency. If regulation strategy of vehicle weight is put in force inappropriately, not only highway cost but also vehicle operating cost will be exposed to grievous losing. However, in the past the studies for VWR have lean to enforcement feasibility and paid less attention on the mechanism of VWR and its long-term impacts. The purpose of this study is to open out the operational mechanism of VWR and to establish the relationships among the freight transportation efficiency, vehicle weight limit, and enforcement validity in theory and reality.The economic, technical and institutional backgrounds of VWR are analyzed and the reason for evolvement of VWR is explained using the new institutional economics methods. A point of view is proposed that VWR is one of the governance structures in highway market to protect the substantive special-assets of highways and to reduce the opportunistic risk in trade-off. The VWR evolution history of several developed countries and China are reviewed and the characteristics of enforcement on over-limit vehicles in China are revealed.Then, the relationships among highway supply, vehicle supply and freight demand are analyzed with microeconomics and engineering methods. A system dynamics (SD) model with five sub-models, such as freight demand, vehicle usage, vehicle operating cost, vehicle evolvement and road performance, is established to simulate the above relationships quantificationally.As an application in Anhui, the long-term performance of highway freight transportation under different VWR strategies is analyzed using above SD model. The empirical results show that the highway freight system has poor sensitivity to fuel price, pavement thickness, pavement maintain interval and road user tax with the situation of ubiquitous overloading and a moderate VWR is necessary to be introduced.Based on theoretical and empirical study, some suggestions aimed at VWR in China are proposed: 1) the legal vehicle weight limit should be moderately increased; 2) a vehicle weight limit framework with national law as lower limit and provincial standards as special limits should be established and; 3) the enforcement efficiency should be enhanced.