In this paper, although there are some useful monitoring methods for short and medium span(10-20m) bridges based on the qualitative or quantitative information, mainly two advanced structural health monitoring systems are described to review and analyses the potential of utilizing the long term health monitoring in safety assessment and management issues for short and medium span bridge. The first system is a special designed mobile in situ loading device (vehicle) for short and medium span road bridges to assess the structural safety (performance) and derive optimal strategies for maintenance using reliability based method. The second system is a long term health monitoring method by using public buses as part of a public transit system (called "bus monitoring system") to be applied mainly to short and medium span bridges, along with a safety index, namely, "characteristic deflection" which is relatively free from the influence of dynamic disturbances due to such factors as the roughness of the road surface, and a structural anomaly parameter.