The aim of the research is to study and determine the effect of speed and road surface roughness on the response of bridges to dynamic loads resulting from truck tire loads. The study variables were truck speed and road surface roughness. The analysis was done for different speeds and different road surface roughness, then the effect of each variable on the response of the bridges was measured. It was clear from results that higher speeds impose greater dynamic loads, which negatively affected the response of the bridges, while the smoother the surface roughness, the more negatively the bridges responded to the dynamic loads. It is clear that increasing speed and smoothness of the road surface negatively affect the response of bridges by increasing the effect of dynamic loads. Therefore, maximum speed limits for trucks that may not exceed 50 km/h, and surface roughness of roads are implemented according to technical standards, are meant to reduce the dynamic effect of loads and their impact on the bridges.