THE MECHANISM OF A ROAD NETWORK

SOME FUNDAMENTAL ASPECTS OF OBSERVED SPEED-DENSITY (CONCENTRATION) RELATIONSHIPS ARE DISCUSSED IN THIS PAPER. THE TOWN CENTER ROAD NETWORK OF A TOWN SUCH AS IPSWICH WITH A POPULATION OF 120,000 IS A COMPLEX MECHANISM. SIMPLE MEASUREMENTS WERE MADE AT THE EVENING PEAK PERIOD AND THE DATA OBTAINED WERE USED TO EXPLAIN THE WORKINGS OF THE MECHANISM OF THE ROAD NETWORK. BRIEFLY, JOURNEY TIME MEASUREMENTS WERE MADE BY THE MOVING OBSERVER METHOD AT PEAK PERIODS OVER A CONSIDERABLE NUMBER OF DAYS AND THE CONCENTRATION WAS DETERMINED FROM A SET OF AERIAL PHOTOGRAPHS TAKEN AT THE PEAK PERIODS. THE NETWORK CONSISTED OF OVER 100 UNIDIRECTIONAL LINKS. VERY FEW LINKS CONSISTED OF MORE THAN ONE TRAFFIC LANE AND ALL WERE COMPARATIVELY VERY SHORT (AVERAGE APPROXIMATELY 1/9 MILE). FOLLOWING THE DATA COLLECTION AND ANALYSIS, A GRAPHICAL MODEL WAS USED TO PREDICT AVERAGE JOURNEY SPEEDS RESULTING FROM SIX CONDITIONS OF NETWORK LOADING THAT VARIED FROM THE OBSERVED PEAK-PERIOD LOAD ON THE SYSTEM. THE RESULTS SUGGESTED THAT THE NETWORK HAD AN INHERENT MINIMUM AVERAGE JOURNEY SPEED WHICH COULD NOT BE REDUCED UNLESS EITHER THE NETWORK WAS PHYSICALLY ALTERED OR AN ARTIFICIAL OBSTRUCTION OCCURRED ON THE NETWORK. /AUTHOR/

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00410683
• Supplemental Notes:
  • Vol 11, pp 323-327
• Corporate Authors:

  N/A

  ,   United States 
• Authors:
  • Godfrey, J W
• Publication Date: 0

Media Info

• Serial:
  • Traffic Engineering & Control
  • Volume: 8
  • Issue Number: 8
  • Publisher: Hemming Group, Limited
  • ISSN: 0041-0683
  • Serial URL: http://www.tecmagazine.com/

Subject/Index Terms

• TRT Terms: Aerial photography; Data collection; Graphics; Networks; Peak hour traffic; Roads; Traffic density; Traffic simulation; Traffic speed; Travel time
• Old TRIS Terms: Graphic methods; Roadnet
• Subject Areas: Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00227249
• Record Type: Publication
• Source Agency: Traffic Systems Reviews & Abstracts
• Files: TRIS
• Created Date: Jun 15 1970 12:00AM