ALIGNMENT COORDINATION IN HIGHWAY DESIGN

THE COORDINATION OF HORIZONTAL AND VERTICAL ELEMENTS OF HIGHWAY ALIGNMENT WERE STUDIED IN ORDER TO PROVIDE SOME DEFINITIVE GUIDELINES FOR THE HIGHWAY DESIGNER. A BATTERY OF COMPUTER PROGRAMS WAS DEVELOPED WHICH PROVIDED A MEANS OF PRODUCING PERSPECTIVE DRAWINGS OF A PROPOSED (OR EXISTING) ROADWAY, RAPIDLY AND ECONOMICALLY. THE PROGRAMS PROVIDED FOR THE COMPUTATION OF: HIGHWAY ALIGNMENT SPACE COORDINATES, THE PERSPECTIVE PICTURE PLANE COORDINATES, AND A "PLOT" PROGRAM, ALL WITH THE OBSERVER (EYE LOCATION) AT ANY ARBITRARILY SELECTED LOCATION. THE CAPABILITIES OF THE COMPUTER PROGRAM ARE DESCRIBED IN DETAIL. MANY OF THE VISUAL DISCONTINUITIES MANIFESTED THEMSELVES AS ABRUPT CHANGES OF CURVATURE IN THE PICTURE PLANE. A COMPUTER PROGRAM TO CALCULATE CURVATURE IN THE PICTURE PLANE WAS DEVELOPED. FURTHER INVESTIGATION INDICATED THAT MANY OF THE VISUAL PROBLEMS WERE CHARACTERIZED MORE BY THE RATE-OF-CHANGE OF CURVATURE THAN OF CURVATURE MAGNITUDE ALONE. THE TECHNIQUE DID SHOW CONSIDERABLE PROMISE BUT NEEDS A GOOD DEAL MORE STUDY. THE FOLLOWING CONCLUSIONS ARE LISTED AS (1) THE P. I.'S, MUST NEARLY COINCIDE (WITHIN ABOUT 10% OF HORIZONTAL CURVE LENGTHS). (2) THE LENGTH OF VERTICAL AND HORIZONTAL CURVES MUST BE NEARLY EQUAL. (WITHIN ABOUT 10%). (3) IF THE CURVES ARE NOT OF THE SAME LENGTH THE HORIZONTAL CURVE SHOULD "LEAD" OR SLIGHTLY PRECEDE THE VERTICAL CURVE, I.E. THE VERTICAL CURVE SHOULD NEVER BE SIGNIFICANTLY LONGER THAN THE HORIZONTAL CURVE. /AUTHOR/

  • Supplemental Notes:
    • Spec Rept 90, 55 PP, 19 FIG, 11 REF, 1 APP
  • Corporate Authors:

    Kansas State Highway Commission

    State Office Building
    Topeka, KS  USA  66612
  • Authors:
    • Smith, B L
    • Murphy, J S
    • Yotter, E E
  • Publication Date: 1970-1-31

Subject/Index Terms

Filing Info

  • Accession Number: 00203591
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Nov 15 1971 12:00AM