Weigh-in-motion for Direct Enforcement of Overloaded Commercial Vehicles

Heavy commercial vehicle (HCV) overloads contribute to premature deterioration of infrastructure and increase road unsafety and unfair competition between transport modes and operators. Public authorities and road operators must therefore implement an efficient checking system to enforce weights and dimensions at an affordable cost. A large scale project was launched in 2014 by the French Ministry of Ecology, Sustainable Development and Sea, in charge of Transport, carried out by French Institute of Science and Technology for Transport (IFSTTAR) and Centre D’etudes et D’expertise sur les Risques, L’environnement, la Mobilite et L’amenagement (CEREMA), to demonstrate the feasibility of using high speed weigh-in-motion (WIM) systems for direct enforcement of overloaded HCVs. This ambitious challenge requires overcoming technological and metrological gaps, and modifying the current legislation. The required tolerances are ±5% for the gross vehicle weight, and ±10% for axle loads. None of the existing WIM system matches this accuracy for 100% of the vehicles. Therefore the objective is to set up some sorting criteria and algorithms, eliminating the weighings outside these tolerances. The project is divided into 5 WPs, to characterize WIM sensor response under controlled environment and loading conditions and to develop fiber optic WIM sensors, to assess the capability of multiple sensor (MS-) and bridge (B-) WIM systems to meet the requirements, to carry long term road tests and to develop type approval procedures for direct enforcement. This paper presents results gathered on the accelerated pavement testing facility of IFSTTAR in 2014 with 10 WIM sensors. Some results of B-WIM systems are also reported. Perspectives are given how to achieve a WIM system type approval procedure for direct enforcement.