Abstract: An automatic transmission control apparatus detects an abrupt loss of vehicle speed from the speed sensor due to failure of the speed sensor. The control apparatus detects a condition of the brake operation so that the abrupt loss of the vehicle speed is detected for transmission control purposes when the brake is under non-operating conditions.

Abstract: A vehicle driver's seat is equipped with an electromagnetically operated vibrator arranged in its back-rest to be activated by energization of an electric control circuit for periodically supplying an electric current to the vibrator from a vehicle battery. A safety device for the driver's seat comprises a parking brake switch arranged between the electric control circuit and the battery to be opened during the inoperative condition of a parking brake of the vehicle and to be closed in response to operation of the parking brake, and an additional control circuit for energizing the electric control circuit in response to closing of the switch to activate the vibrator during arrest of the vehicle and for deenergizing the electric control circuit in response to opening of the switch to deactivate the vibrator during movement of the vehicle.