Patent ID: 8079649

Claim:
A brake system for a vehicle comprising: at least one source of pressurized air for pressurizing the vehicle brake system; a brake actuator configured to receive air from the source of pressurized air; a control operatively associated with the source of pressurized air for selective application of the brake actuator; and a supplemental parking brake control system in communication with the control and the brake actuator, the control system: including a plurality of inputs, individual inputs indicative of a predetermined vehicle condition, the vehicle conditions including (i) a parking condition of the vehicle, (ii) a gradient of a road on which the vehicle is to be held stationary, (iii) a speed of the vehicle and (iv) a state of a vehicle ignition; responsive to data indicative of gradient and speed vehicle conditions; configured to send a signal to the brake actuator to allow gradient and speed dependent supplemental parking; and configured to prevent application of the brake actuator.