In an experiment at the 5-arm county island roundabout in Swindon, the capacity of the original roundabout was compared with that of various experimental roundabout layout within the same outline of 75 x 85M. A reduction of the central island from an oblong 60 x 75M to a circle of 38M diameter increased the capacity by about 33 per cent to 6840 pcu/h. A change to a ring junction, ie two-way circulation with a mini-roundabout at the mouth of each of the five roads, increased the capacity by 20 per cent over that of the original. The operation of the various layouts tested is discussed. (A) /TRRL/

  • Corporate Authors:

    Transport and Road Research Laboratory (TRRL)

    Wokingham, Berkshire  United Kingdom 
  • Authors:
    • Halsall, R C
    • Blackmore, F C
  • Publication Date: 1975

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 28 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00132217
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: TRRL SR 145UC R&D Rept.
  • Files: ITRD, TRIS
  • Created Date: Sep 4 1976 12:00AM