A safety rail assembly for mounting on a deck of a transport carrier which transports and supports thereon at least one automobile having at least one of passenger and driver-side doors. The portable safety rail assembly includes a handrail extending horizontally relative to the upper surface of the deck and support posts for supporting the handrail. Each support post may be removeably mounted to the deck to permit selective vertical displacement of the handrail relative to the upper surface of the deck for positioning the handrail at a desired height above the upper edge of a door of the transported vehicle. The desired height permits unobstructed opening and closing of the doors and safe entrance into and egress from the interior of the automobile.