A GUIDE FOR PROTECTIVE SCREENING OF OVERPASS STRUCTURES

THE PROBLEM OF PREVENTING OBJECTS FROM BEING DROPPED OR THROWN FROM OVERPASS WALKS ONTO VEHICLES TRAVELLING BELOW HAS INCREASED WITH THE INCREASE OF FREEWAY DEVELOPMENT. REPORTS OF LARGE OBJECTS FALLING THROUGH WINDSHIELDS AND FATALLY INJURING OCCUPANTS HAVE BEEN RECEIVED FROM MANY AREAS. THERE IS NO PRACTICAL DEVICE OR METHOD THAT CAN UNIVERSALLY PREVENT A DETERMINED INDIVIDUAL FROM THE ACT; IN SOME CASES THE PREVENTIVE MEASURE ACTS AS A MOTIVATING CHALLENGE. BETTER POLICE SURVEILLANCE HAS HELPED IN SOME CASES, BUT CONSTANT SURVEILLANCE OF EVERY OVERPASS IS IMPOSSIBLE. FOR PEDESTRIAN OVERPASSES, A 6-8 FOOT HIGH CHAIN-LINK FENCE HAS PROVED EFFECTIVE IN KEEPING CHILDREN FROM PLAYING ON THE PARAPET, BUT OBJECTS CAN BE HURLED OVER IT. A RECTANGULAR ENCLOSURE OF CHAIN-LINK FENCING INVITES CHILDREN TO CLIMB IT AND HAS LED TO AT LEAST ONE FATALITY. DESIGNS WITH A CIRCULAR SHAPE, COMPLETELY COVERED OR ONLY PARTIALLY ENCLOSED HAVE BEEN MOST EFFECTIVE. FOR VEHICULAR AND PEDESTRIAN OVERPASSES, BOTH CHAIN-LINK FENCING AND SHEET METAL FENCING HAVE BEEN EFFECTIVE, THE LATTER HAVING THE ADVANTAGE OF SCREENING THE VIEW. LOCATIONS WHERE SCREENS SHOULD BE CONSIDERED DURING OVERPASS CONSTRUCTION ARE THOSE NEAR SCHOOLS AND PLAYGROUNDS AND THOSE IN LARGE URBAN AREAS WHERE POLICE SURVEILLANCE IS DIFFICULT. NATURALLY SCREENS SHOULD BE INSTALLED ON EXISTING STRUCTURES WHERE "OVERPASS BOMBING" INCIDENTS HAVE OCCURRED.

  • Supplemental Notes:
    • 16 Pp, 10 FIG
  • Corporate Authors:

    American Association of State Highway Officials

    444 North Capitol Street, NW
    Washington, DC  USA  20001
  • Publication Date: 1968-12

Subject/Index Terms

Filing Info

  • Accession Number: 00220750
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 13 1970 12:00AM