Observations were made of traffic delays before and after the 35 m diameter small-island layout was introduced. The "before" study covered the period prior to any alternation of the original roundabout layout, whilst the "after" study was carried out 8 months after completion of the new roundabout traffic capacity experiment. The pattern of traffic movements through the intersection during both morning and afternoon peak hours and typical off-peak periods were recorded, as well as traffic delay during these periods. The results confirm that the increased capacity shown in observations has led to a reduction in delays to vehicles despite increases of 8 to 10 percent in the peak hour traffic volumes. Peak hour delays are estimated to have been reduced by some 3500 veh-hr per annum.

  • Supplemental Notes:
    • Presented at Seminar X (Road Design 1: General Topics) of the PTRC Summer Annual Meeting, Warwick University, England, 8-12 July 1974.
  • Corporate Authors:

    Planning and Transport Res and Computation Co Ltd

    167 Oxford Street
    London W1R 1AH,   England 
  • Authors:
    • Ashworth, R
  • Publication Date: 1974-7

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00096286
  • Record Type: Publication
  • Report/Paper Numbers: PTRC/P/108
  • Files: TRIS
  • Created Date: Sep 10 1975 12:00AM