MEDIAN STUDY (CALIFORNIA)

ON THE BASIS OF BOTH TOTAL ACCIDENTS AND CASUALITY ACCIDENTS, TRAVERSABLE DIVIDED AND DETERRING EARTH MEDIANS WERE UNIFORMLY LOW IN THIS STUDY. OTHER DETERRING MEDIANS SHOW LOWER RATES THAN THE UNDIVIDED WITH ALL TYPES OF NONTRAVERSABLE MEDIANS EXHIBITING SUBSTANTIALLY THE HIGHEST RATES. WHEN THE SAMPLE WAS SORTED ON THE BASIS OF MEDIAN WIDTH, THE LOWEST ACCIDENT AND INJURY ACCIDENT RATES FOR DETERRING MEDIANS WERE DEFINITELY IN THE 4-TO-6-FT. RANGE. TRAVERSABLE MEDIANS SHOWED LOWEST TOTAL ACCIDENT RATES IN THE 6-TO-10-FT. RANGE AND LOWEST INJURY ACCIDENT RATES IN THE 20-TO-30-FT. WIDTH GROUP. A BREAKDOWN ON THE BASIS OF TYPE OF ACCIDENT SHOWS THAT APPROACH-TYPE ACCIDENTS ARE SIGNIFICANT ONLY FOR THE UNDIVIDED HIGHWAY. OVERTAKING ACCIDENTS INCREASE SLIGHTLY FROM TRAVERSABLE TO NONTRAVERSABLE MEDIANS. THE SINGLE- VEHICLE-ACCIDENT RATE FOR NON-TRAVERSABLE MEDIANS IS DOUBLE THAT FOR OTHER TYPES. ON THE BASIS OF SEVERITY, DETERRING TYPES OF MEDIANS ARE LOWEST IN CASUALTY ACCIDENTS PER MILLION VEHICLE MILES (MVM), CASUALTIES PER MVM, AND CASUALTIES PER 100 ACCIDENTS. NONTRAVERSABLE MEDIANS HAVE MARKEDLY HIGHER RATES THAN ALL OTHER TYPES FOR CASUALTY ACCIDENTS AND CASUALTIES PER MVM, BUT THE HIGHER PERCENTAGE OF MULTIPLE-VEHICLE ACCIDENTS OCCURRING ON TRAVERSABLE MEDIANS RESULTS IN THIS GROUP HAVING THE HIGHEST NUMBER OF CASUALTIES PER 100 ACCIDENTS. IN TOTAL ACCIDENTS INVOLVING THE CENTER DIVISION, NONTRAVERSABLE MEDIANS EXHIBITED A SUBSTANTIALLY HIGHER RATE THAN THE OTHER TYPES. CROSSED-CENTER-DIVISION ACCIDENTS INCREASED SHARPLY WITH DEGREE OF TRAVERSABILITY, WHILE ACCIDENTS INVOLVING HITTING OR ENTERING THE CENTER DIVISION VARIED INVERSELY WITH TRAVERSABILITY. HITTING AN OBJECT IN THE CENTER DIVISION OCCURRED FIVE TIMES AS OFTEN ON NONTRAVERSABLE MEDIANS. IN COMPARING NARROW AGAINST WIDE MEDIANS ON A BASIS OF TRAFFIC VOLUME, CURVES ARE SUBSTANTIALLY PARALLEL UP TO 15,000 VEHICLES PER DAY. BEYOND THIS TRAFFIC VOLUME, PER DAY. BEYOND THIS TRAFFIC VOLUME, NARROW MEDIANS SHOW A SLIGHTLY HIGHER RATE FOR DAYLIGHT ACCIDENTS AND A MATERIALLY HIGHER RATE FOR NOT-DAYLIGHT ACCIDENTS. WIDER MEDIANS APPARENTLY HAVE AN ADVANTAGE UNDER HIGHER-TRAFFIC VOLUMES. /AUTHOR/

  • Supplemental Notes:
    • Vol 32, pp 208-231, 5 FIG, 11 TAB, 10 PHOT, APP
  • Authors:
    • Telford, E T
    • ISRAEL, R J
    • Loutzenheiser, D W
  • Publication Date: 1953

Media Info

  • Monograph Title: Proceedings of the Thirty-Second Annual Meeting of the Highway Research Board, Washington, D.C., January 13-16, 1953
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00203561
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 15 1971 12:00AM