GETTING THE BEST ROADS FOR OUR MONEY. THE COBA METHOD OF APPRAISAL

THIS BOOKLET DESCRIBES A NEW METHOD OF ECONOMIC APPRAISAL WHICH IS BEING INTRODUCED BY THE DEPARTMENT OF THE ENVIRONMENT, FOR INTER-URBAN ROAD SCHEMES. THE NEW METHOD CALLED COBA, A COMPUTER PROGRAM, APPLIES DISCOUNTING METHODS TO THE APPRAISAL OF ROAD SCHEMES. IT CALCULATES AND DISCOUNTS THE COSTS AND TRAFFIC BENEFITS OF A ROAD SCHEME OVER AN ASSUMED 30 YEAR LIFE, GIVING AT THE END THE SCHEMES NET PRESENT VALUE AND THE RATIO OF NEW PRESENT VALUE TO CAPITAL COST. IT ALSO CALCULATES IN A STANDARD FASHION, JUNCTION DELAYS, AND MAJOR IMPROVEMENTS IN ACCURACY HAVE RESULTED FROM THE ADOPTION OF DISCOUNTING. BENEFITS TO TRAFFIC CAN WITH THIS METHOD BE CALCULATED OVER COMPLETE YEARS AND, IN PARTICULAR OVER THE FULL 24 HOURS OF THE DAY, WHERE AS WITH EARLIER METHODS BENEFITS WERE SIMPLY CALCULATED FOR THE ANNUAL AVERAGE TRAFFIC LEVEL. OTHER IMPORTANT APPLICATIONS OF COBA INCLUDE ITS USE IN PROVIDING A PROPER ASSESSMENT OF A SET OF PROJECTS WHICH ARE RELATED TO EACH OTHER IN TRAFFIC TERMS AND PHASED OVER TIME, AND ITS USE IN GIVING EFFICIENT SOLUTIONS TO DESIGN PROBLEMS SUCH AS ALIGNMENT, TYPE OF CARRIAGEWAY AND JUNCTION TREATMENT.

  • Corporate Authors:

    Her Majesty Stationary Office

    49 High Holborn
    London WC1V 6HB,   England 
  • Authors:
    • Doe
  • Publication Date: 1972

Media Info

  • Features: Figures; Tables;
  • Pagination: 17 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00202529
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: R & D Rept
  • Files: TRIS, ATRI
  • Created Date: Mar 15 1974 12:00AM