Depending upon the all-in-one real-time monitor system of 16 bridges on Xiangxi and Yanhainan highways of Xiangshan County, Zhejiang Province, based on fiber grating sensing technology, the identification of running heavy duty vehicles and their weights is achieved without investing the additional weighting systems at the bridgeheads. Employing high-speed data acquired by fiber grating strain sensors, the weights, space-time distribution of heavy duty vehicles can be identified by means of physical analyses, which is useful for monitoring and evaluating the operation status of bridges with heavy duty vehicles running. The statistical records of heavy duty vehicles are also beneficial to devise relevant bridge maintenance and management measurements.