ZAHAVI'S ALPHA RELATION: MYTH OR BLESSING

Zahavi's alpha model may be thought of as a macro relation representing the whole or a vast sector of an urban transport network in a simplified fashion for project evaluation. It allows to estimate, for example, the average speed of a transport system if the number of vehicle-km travelled on it are known, given certain attributes of the system such as the length of its trunk road network and the value of the constant alpha. This paper starts by calculating a value of alpha for Santiago, which was found to differ markedly from the universal figure of 400000 supported by zahavi. Some reasons for this are discussed in the paper. It concludes with a discussion of a novel application of the alpha model to the estimation of the number of kilometers of trunk road construction that could be saved by implementing certain public transport network improvement projects (like extending the underground), such as to guarantee in the future a minimum average operating speed in the city.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03918440
• Corporate Authors:

  IJTE

  8 VIA G A GUATTANI
  Roma, 00161, ZZ Italie   

  IJTE

  8 VIA G A GUATTANI
  Roma, 00161, ZZ Italie   
• Authors:
  • Ortuzar, J D
• Publication Date: 1988-6

Language

• English

Media Info

• Pagination: p. 190-201
• Serial:
  • International Journal of Transport Economics
  • Volume: 15
  • Issue Number: 2
  • ISSN: 0391-8440
  • Serial URL: http://www.libraweb.net/riviste.php?chiave=67

Subject/Index Terms

• TRT Terms: Length; Mathematical models; Networks; Roads; Speed; Urban areas
• Uncontrolled Terms: Road networks; Transportation networks
• Geographic Terms: Chile
• ITRD Terms: 6549: Average; 8022: Chile; 6488: Length; 6473: Mathematical model; 1054: Network (traffic); 744: Public transport; 1053: Road network; 5408: Speed; 755: Traffic; 1155: Transport; 313: Urban area
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00482037
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: ITRD, TRIS, ATRI
• Created Date: Apr 30 1989 12:00AM