USE OF AERIAL SURVEYS AND TOPOGRAPHIC MAPS FOR PROJECTING HIGHWAY ALIGNMENT

BY INTRODUCING MODERN METHODS OF HIGHWAY PROJECTION AND THE EFFICIENT USE OF TOPOGRAPHIC MAPS DEVELOPED FROM PHOTOGRAMMETRY, THE LOCATION ENGINEER CAN ESTABLISH ALIGNMENT AND GRADES WHICH COMPLEMENT THE TOPOGRAPHY AND ELIMINATE NEARLY ALL OF THE UNDESIRABLE ASPECTS OF THE OLDER ACCEPTED METHODS OF GROUND LOCATION. IN ORDER TO PROJECT ACCURATE HIGHWAY ALIGNMENT, A COORDINATE GRID SYSTEM MUST BE ESTABLISHED OVER THE AREA THROUGH WHICH THE LOCATION IS TO PASS. THE FINAL RESULTS OF ANY LINE PROJECTED THROUGH THIS AREA WILL BE NO MORE ACCURATE THAN THE ORIGINAL CONTROL USED TO ESTABLISH THE GRID SYSTEM. THE PRESENT PAPER IS BASED ON THE ASSUMPTION THAT THE TOPOGRAPHIC MAP THROUGH WHICH THE HIGHWAY ALIGNMENT IS TO BE PROJECTED IS ACCURATE BOTH HORIZONTALLY AND VERTICALLY, THAT PRE-ESTABLISHED HORIZONTAL AND VERTICAL CONTROL POINTS ARE IN USABLE POSITIONS, AND PLANIMETRIC FEATURES AS WELL DEFINED. SIMPLE AND ACCURATE METHODS OF CALCULATING CURVE POSITIONS BY COORDINATES, SIMPLE PROCEDURES FOR PROJECTING CENTERLINE WHERE GRADE OR LAND USE PROBLEMS EXIST, THE EFFECTIVE USE OF THE SPLINE, SIMPLIFIED USE OF SPIRAL TRANSITIONS AND A SIMPLIFIED, ACCEPTABLY ACCURATE BUT APPROXIMATE, METHOD OF INTRODUCING TRANSITIONS BETWEEN COMPOUND CURVES ARE DISCUSSED. THROUGH INTELLIGENT USE OF THE COORDINATE METHOD OF CENTERLINE PROJECTION, EMPLOYING AN ACCURATE TOPOGRAPHIC MANUSCRIPT, COMPILED BY PHOTOGRAMMETRIC METHODS, BETTER HIGHWAY LOCATIONS CAN BE ACHIEVED ALONG WITH A SUBSTANTIAL SAVINGS IN MAN-HOURS. /AUTHOR/

Media Info

  • Monograph Title: Photogrammetry: developments and applications, 1960
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00202683
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Sep 3 1994 12:00AM