Vehicle-induced bridge vibrations has become an important issue for the dynamic response of bridges especially after the achievement of long spans by cable-stayed bridges during the last two decades. In this study, the effects of vehicle speed, which is one of the important parameters of vehicle-bridge interaction, and variations in the speed are investigated to determine the bridge responses. Tatara bridge which is the second largest cable-stayed bridge in the world, is considered by 3-D finite element model. Two sets of traffic load combinations are applied for three different vehicle speed values and analyses are conducted to evaluate the speed induced dynamic responses of the bridge. The largest responses in the bridge are generally observed for low speeds. On the other hand, larger responses begin to occur in the mid-span after the vehicles leave the mid-span of the bridge for higher speeds.