A step apparatus for a vehicle with a rear impact guard beam includes top and bottom steps mounted on a step frame adapted to be pivotally attached to the rear impact guard beam about a step pivot axis oriented horizontally and perpendicular to an operating travel direction of the vehicle. The step frame is movable from an operating position to a stored position. A roller is mounted to a bottom rear end of the step frame about a roller rotational axis oriented parallel to the step pivot axis, and located above the step pivot axis. An upright surface moving toward the step frame contacts the roller component and the roller rolls upward along the upright surface and pivots the step frame about the step pivot axis from the operating position to the stored position.