Abstract This paper presents numerical studies using the model of the three‐dimensional train–wheel–bridge–bearing (TWBB) system. The system responses under train‐induced excitation only, earthquake excitation only, and combined train‐induced plus earthquake excitation are evaluated in terms of structural safety, running safety, and ride comfort. By coupling the subsystem models, these numerical simulations require just seconds to execute, exhibiting high computational efficiency. Based on the simulation results, the main conclusion is that although the bearings may reduce the seismic bridge responses, they also are likely to deteriorate the train's running safety and ride comfort. Therefore, there is a requirement in future bearings design procedures for railway bridges to find a balance between the bridge and train seismic responses.