Abstract: To support the development of intelligent assessment and management system of bridges under customized transportation vehicle (CTV) in many provinces of China, an assessment method was developed by considering the requirements of safety and serviceability simultaneously. The bridge assessment method framework under CTV was proposed by including the requirements of safety and serviceability. In addition, the target reliability indices for assessment, the calibration of partial factors and the determination of critical load effect ratios were investigated according to reliability theory. Case studies were carried out by selecting the typical small-to-medium span bridges of expressway. For the CTVs not satisfying the passage requirements, the systematic passage supporting strategy was provided. It is found that the assessment method should be stricter with the increasing of CTV traffic volume. The ranges of partial factors of dead load effect, CTV load effect and resistance are 1.069, 1.077、1.115, 1.131 and 1.165, 1.225, respectively, when the annual average traffic volume of CTV is considered as 50~200. The safety assessment results of bridge components are significantly influenced by the technical levels, and the annual average traffic volume of CTV has obvious influences on the serviceability assessment results.