A ramp door and door frame include a rail kit that deploys automatically when the door is opened and collapses automatically when the door is closed. The door is supported by a cable mechanism when the door is opened. The cable mechanism causes an end rail to pivot up and away from the door when the door is opened and down and toward the door when the door is closed. The end rail cooperates with a door frame to deploy flexible side barriers when the door is opened and to collapse the side barriers when the door is closed.