This research was conducted on the truck weight identification while moving on the bridge. The moment signals from various bridge sections, truck velocity, number of axles, the distance between axles were used as input data. The main objective of the research is to improve the existing identification accuracy by adopting the iteration technique. Moreover, the iteration method was used to facilitate in this calculation in order to increase the accuracy of the result. In the first part, the model of a truck traveling on a bridge was simulated using computer. The influences from various variables on identification accuracy such as parameter (λ), truck velocity, rough surface of the bridge, ratio of front axle weight to back axle weight, and spring stiffness of the axle were studied. As a result, it was found that the velocity and the roughness of the surface have more influence than other variables. In the second part, the scaled models of the truck and the bridge were constructed and were employed instead of the previous computer models used in the first part. With these experimental models, the accuracy of truck weight identification was again studied. About 96 case of experiment having various truck weights, truck speeds and the weight ratios of front axle to rear axle were conducted. Based on the obtained results, it was found that the iteration technique can substantially improve the identification accuracy over the conventional method. This improvement raises the accuracy to be within 5%, 12% and 39% for total, rear axle and front axle weights, respectively.
