Abstract: An illumination system for a semi-tractor and trailer includes a pair of illumination housings, one attached to either side of the trailer just above the rear wheels. A reflector within each housing reflects light from a light source downward and outward through a clear lens to encompass an arc extending from the vertical to a predetermined angle, e.g. approximately 45 degrees from vertical. Light is thus directed onto the pavement and any objects immediately adjacent the trailer rear wheels to aid the driver in close quarter maneuvering, turns, and when changing highway lanes. A control circuit is connected to each light source and to the turn signal lead on the respective trailer side to provide steady power to the light source only when the turn signal and/or emergency flasher circuit is enabled. An optional amber lens can be provided on the side of each illumination housing to resemble the ordinary running lights on a typical semi-trailer.