For regulating the speed of a motor vehicle, a control apparatus is equipped with an object detection system, and the reference speed is determined as a function of at least one preceding vehicle in the evaluation region of the object detection system, such that upon recognition of an imminent lane change by the regulated vehicle, vehicles in the adjacent destination lane are additionally taken into consideration for calculation of the reference speed by expanding the evaluation region in the direction of the destination lane, and consideration is given only to vehicles in the destination lane whose distance from the regulated vehicle is less than a predetermined distance value.