A study has been performed to identify damages to and evaluate the effectiveness of the metal median barrier on the Schuylkill expressway, Philadelphia, in relation to accident occurrence, volume and geometric design, using photography. The median barrier in Montgomery and Philadelphia counties was photographed for approximately 20 miles using 35-mm strip file, which was then viewed on a dual projector console developed for the Pennsylvania department of highways. The total number of various type median barrier damages detected in the 12-month study period was 1085. Though the traffic volume seemingly had little effect on the number of damages, the geometric designs influence was in evidence with interchange areas and curves showing considerably more impacts. Police accident reports were also studied both before and after the installation of the barrier to determine the effect it had on the number, type, and severity of accidents. /author/.
Abstract