Abstract: A parking brake engagement indicator for a parking brake system on a commercial truck wherein an indicator bar is mounted on the truck and is moveable between a position of impediment between the driver's outside lower leg portion and the driver's side exit doorframe of the truck, to a second position of non-impediment. The indicator bar is connected to the parking brake system whereby the bar is manipulated by the brake system itself to the position of impediment when the parking brake is disengaged and the bar is manipulated by the brake system to the position of non-impediment when the parking brake is engage.