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ACCIDENT AND ECONOMIC ANALYSES OF ACCESS CONTROL ON SEVERAL BYPASSES

IN THIS STUDY, ACCIDENT REPORTS WERE OBTAINED FOR SEVERAL BYPASSES ACROSS KENTUCKY AND THEN ANALYZED TO DETERMINE IF THEY COULD HAVE BEEN PREVENTED WITH ACCESS CONTROL AND GRADE SEPARATED INTERCHANGES. AN ACCIDENT WAS CLASSIFIED AS "CORRECTABLE" IF IT COULD HAVE BEEN PREVENTED. OF 518 ACCIDENTS ON THE SUBJECT BYPASSES DURING THE STUDY PERIOD, 397 (76.6 PERCENT) WERE CLASSIFIED AS CORRECTABLE. OF A TOTAL OF 271 INJURIES, 234 (86.3 PERCENT) WERE THE RESULT OF CORRECTABLE ACCIDENTS; OF THE 14 FATALITIES, 12 (85.7 PERCENT) WERE THE RESULT OF CORRECTABLE ACCIDENTS. IT WAS ALSO SHOWN THAT APPROXIMATELY 70 PERCENT OF THE ACCIDENTS OCCURRED AT GRADE INTERSECTIONS, INDICATING THESE INTERSECTIONS HAVE CREATED THE MOST SERIOUS ACCIDENT POTENTIAL. SOME ACCIDENTS, OF COURSE, WOULD OCCUR BY OTHER MEANS IF INTERCHANGES HAD BEEN BUILT. HOWEVER, THE TOTAL NUMBER OF ACCIDENTS AND THEIR SEVERITY WOULD BE GREATLY REDUCED. IT WAS SHOWN THAT INJURY ACCIDENTS WOULD BE REDUCED MORE THAN PROPERTY DAMAGE ACCIDENTS BECAUSE THE RIGHT ANGLE ACCIDENT HAD THE GREATEST ACCIDENT SEVERITY, AND IT IS ALSO THE TYPE OF ACCIDENT THAT WOULD BE THE MOST CORRECTABLE. WITH ATGRADE INTERSECTIONS, THE ONLY SOLUTION TO THE RIGHT ANGLE COLLISIONS, THE NUMBER OF REAREND ACCIDENTS AND POSSIBLY THE TOTAL NUMBER OF ACCIDENTS WILL INCREASE, AND TIME AND OPERATING COSTS WILL ALSO INCREASE. THE CRITICAL ELEMENT WAS TO DETERMINE WHETHER THE REDUCTION IN ACCIDENT, TIME AND OPERATING COSTS WOULD JUSTIFY THE HIGHER INITIAL EXPENSE INVOLVED IN BUILDING BYPASSES WITH INTERCHANGES AND ACCESS CONTROL. OF 35 MAJOR INTERSECTIONS INVESTIGATED, 16 HAD BENEFIT COST RATIOS GREATER THAN ONE. OF THE 19 WHICH HAD A BENEFIT COST RATIO LESS THAN ONE, NINE WERE CLASSIFIED AS A HAZARDOUS LOCATION BY VIRTUE OF THEIR ACCIDENT EXPERIENCE. GENERALLY, SIGNALIZED INTERSECTIONS HAD HIGHER BENEFIT COST RATIOS BECAUSE OF THE HIGH VOLUME OF TRAFFIC REQUIRED TO STOP. WHILE ACCIDENT COSTS CLEARLY HAD AN EFFECT ON THE BENEFIT COST RATIO, IT WAS APPARENT THAT THE TIME COST AND OPERATION COST WERE THE MORE SIGNIFICANT FACTORS IN A MAJORITY OF CASES. IT WAS SHOWN IN MOST CASES THAT IT WOULD BE WARRANTED AND ECONOMICALLY JUSTIFIABLE TO BUILD AN INTERCHANGE AT AN INTERSECTION WHERE A RELATIVELY HIGH VOLUME OF TRAFFIC WOULD BE REQUIRED TO STOP OR WHERE A HAZARDOUS LOCATION COULD BE ELIMINATED.

Media Info

  • Features: Figures; Photos; Tables;
  • Pagination: 104 p.
  • Serial:
    • Issue Number: 341

Subject/Index Terms

Filing Info

  • Accession Number: 00224309
  • Record Type: Publication
  • Files: TRIS, STATEDOT
  • Created Date: Oct 9 1973 12:00AM