RELATIONSHIP OF VEHICLE PATHS TO HIGHWAY CURVE DESIGN

CURRENT DESIGN PRACTICE FOR HORIZONTAL CURVES ASSUMES THAT VEHICLES FOLLOW THE PATH OF THE HIGHWAY CURVE WITH GEOMETRIC EXACTNESS. TO EXAMINE THE ADEQUACY OF THIS ASSUMPTION, PHOTOGRAPHIC FIELD STUDIES WERE CONDUCTED OF VEHICLE MANEUVERS ON HIGHWAY CURVES. RESULTS OF THE FIELD STUDIES INDICATE THAT MOST VEHICLE PATHS, REGARDLESS OF SPEED, EXCEED THE DEGREE OF HIGHWAY CURVE AT SOME POINT ON THE CURVE. FOR EXAMPLE, ON A 3-DEGREE HIGHWAY CURVE, 10 PERCENT OF THE VEHICLES CAN BE EXPECTED TO EXCEED 4.3 DEGREES. A NEW DESIGN APPROACH IS PROPOSED. THIS APPROACH IS DEPENDENT UPON SELECTING: AN APPROPRIATE VEHICLE PATH PERCENTILE RELATION; A REASONABLE SAFETY MARGIN TO ACCOUNT FOR UNEXPLAINED VARIABLES THAT MAY EITHER RAISE THE LATERAL FORCE DEMAND OR LOWER THE AVAILABLE SKID RESISTANCE, AND A MINIMUM SKID RESISTANCE VERSUS SPEED RELATIONSHIP THAT THE HIGHWAY DEPARTMENT WILL PROVIDE ON ALL PAVEMENTS. /AUTHOR/

• Supplemental Notes:
  • Res Rept 134-5, 69 PP
• Corporate Authors:

  Texas Transportation Institute

  Texas A&M University System, 1600 E Lamar Boulevard
  Arlington, TX  United States  76011
• Authors:
  • Glennon, J C
  • Weaver, G D
• Publication Date: 1971-5

Subject/Index Terms

• TRT Terms: Highway curves; Highway design; Photography; Skid resistance; Surveys; Vehicle dynamics
• Uncontrolled Terms: Photographic surveys; Vehicle path
• Subject Areas: Design; Highways;

Filing Info

• Accession Number: 00203614
• Record Type: Publication
• Files: TRIS
• Created Date: Mar 27 1972 12:00AM