A newly obtained wheel speed of a drive wheel is not used in a calculation for acceleration slip when a vehicle is stopped, for example, when the wheel speed of a rolling wheel is zero and an engine speed is high. A wheel speed calculated before a previous wheel speed is, for example, set as a current wheel speed. In this manner, even if the wheel speed of a driving wheel is due to the effect of racing noise, it is possible to limit erroneous determinations that indicate acceleration slip is being generated, based upon such a wheel speed. In addition, unnecessary execution of a traction control can also be curbed.