EVALUATION OF TRANSITION CURVES ON TWO-LANE RURAL HIGHWAYS - FINAL REPORT

GEOMETRIC DESIGN RELATIONSHIPS, THOUGH DEVELOPED FROM THEORETICAL CONSIDERATIONS, ARE GREATLY INFLUENCED BY PRACTICAL CONSIDERATIONS. DIFFERING DESIGN STANDARDS EXIST BECAUSE OF VARYING OPINIONS ON UNQUANTIFIED TRAFFIC FLOW SITUATIONS. ONE DIFFERENCE EXISTS IN THE APPLICATION OF TRANSITION CURVES IN THE DESIGN OF HORIZONTAL ALINEMENT, AS MEASURED BY CHANGES IN VEHICLE PLACEMENT ON A CURVE. THE MOVEMENT OF VEHICLES THROUGH BOTH SPIRALED AND UNSPIRALED CURVES WAS ANALYZED TO TEST THE HYPOTHESIS THAT THESE CURVES CAUSE SIMILAR CHANGES IN LATERAL PLACEMENT OF THE VEHICLES. THE STUDY SHOWED THAT THE PATHS OF VEHICLES ARE AFFECTED BY THE USE OF SPIRALS ON HORIZONTAL CURVES. VEHICLES WERE FOUND TO TRAVERSE A NONSPIRALED CURVE WITH A MORE CONSTANT LATERAL PLACEMENT FROM THE CENTERLINE THAN THEY DID A SPIRALED CURVE. OTHER MAJOR FINDINGS OF THE STUDY FOR BOTH SPIRALED AND NONSPIRALED CURVES WERE: TRUCK COMBINATIONS TRAVEL FURTHER FROM THE CENTERLINE ON A HORIZONTAL CURVE THAN DO AUTOMOBILES OR SINGLE-UNIT TRUCKS; THE PATHS OF VEHICLES RELATIVE TO THE ROADWAY CENTERLINE ARE DIFFERENT FOR ENTERING AND LEAVING A CURVE, AND FOR THE INSIDE AND OUTSIDE OF THE CURVE; AND THE DEGREE OF CURVE AFFECTS THE LATERAL PLACEMENT OF THE VEHICLE. /AUTHOR/

  • Supplemental Notes:
    • APP
  • Corporate Authors:

    Purdue University/Indiana Department of Transportation JHRP

    Purdue University, School of Civil Engineering
    West Lafayette, IN  USA  47907-1284
  • Authors:
    • Lyford, R W
  • Publication Date: 1972-6-22

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 75 p.
  • Serial:
    • Issue Number: 7

Subject/Index Terms

Filing Info

  • Accession Number: 00203667
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Nov 28 1972 12:00AM