EVALUATION OF STOPPING SIGHT DISTANCE DESIGN CRITERIA

AN EXAMINATION OF THE STATE OF KNOWLEDGE WAS CONDUCTED TO EVALUATE DESIGN CRITERIA FOR SAFE STOPPING SIGHT DISTANCE. THE EVALUATION WAS SPECIFICALLY CONCERNED WITH DRIVER PERCEPTION-REACTION TIME, DESIGN FRICTION FACTORS, ASSUMED SPEEDS FOR DESIGN, DRIVER'S EYE HEIGHT, AND OBJECT HEIGHT. THE DESIGN CRITERIA WERE EXAMINED THAT ARE PRESENTED IN "A POLICY ON GEOMETRIC DESIGN OF RURAL HIGHWAYS, 1965," BY THE AASHO. THE MAJOR FINDINGS WERE: (1) DRIVER PERCEPTION-REACTION TIME MAY BE HIGHER THAN THE ASSUMED 2.5 SECONDS FOR THE HIGHER TRAVEL SPEEDS; (2) BASED ON SKID TRAILER MEASUREMENTS ON 500 PAVEMENTS, IT WAS CONCLUDED THAT THE AASHO DESIGN FRICTION FACTOR VALUES DO NOT REPRESENT A CRITICAL LEVEL OF STOPPING CAPABILITY; (3) THE AASHO'S "ASSUMED SPEED FOR CONDITIONS" HAS NO OBJECTIVE BASIS, WHILE ALTERNATIVE BASES ARE AVAILABLE; (4) THE PRESENT CRITERION FOR OBJECT HEIGHT BEARS NO RELATION TO MANY OF THE OPERATIONAL REQUIREMENTS FOR SAFE STOPPING SIGHT DISTANCE; AND (5) THERE IS A NEED TO DESIGN FOR NIGHTTIME STOPPING SIGHT DISTANCE TO OPPOSING VEHICLE HEADLIGHTS ON TWO-LANE HIGHWAYS. /AUTHOR/

  • Supplemental Notes:
    • 71 Pp, 15 FIG, 9 TAB, 19 REF, 3 APP
  • Corporate Authors:

    Texas Transportation Institute

    Texas A&M University System, 1600 E Lamar Boulevard
    Arlington, TX  USA  76011
  • Authors:
    • Glennon, J C
  • Publication Date: 1969-8

Subject/Index Terms

Filing Info

  • Accession Number: 00203455
  • Record Type: Publication
  • Files: TRIS, ATRI
  • Created Date: Sep 14 1970 12:00AM