Railway bridges are susceptible to over-height truck collisions and to address this issue, it is necessary to attenuate the effect of these impacts to ensure the safety of transportation operations. This study experimentally investigates the effectiveness of crash beams as a cushioning mechanism for railway bridges against collisions. Over-height truck and railway bridge impact events were simulated in a 1:5 scale experiment. The design parameters such as the stiffness of the crash beam and the bridge supports were scaled to evaluate different levels of attenuation. Seventeen experiments were conducted with five configurations consisting of four different types of crash beams and one no-crash beam arrangement. The results show that crash beams attenuate bridge total peak dynamic displacement responses between 14.5％ and 35.7％, depending on the intensity of the impact and crash beam type. In addition, the results show that the average effectiveness in attenuating residual deformation for all four crash beams ranges from 43.03％ to 83.40％. Finally, various designs and their effectiveness against lateral impacts with different speeds are discussed. The overall scope of this research is to provide objective information about the design of crash beams for railway bridges based on their response to over-height truck collisions at various speeds.