THE IMPACT ON ACCIDENTS OF THE INTRODUCTION OF MINI, SMALL AND LARGE ROUNDABOUTS AT MAJOR/MINOR PRIORITY JUNCTIONS

A study of accidents close to mini, small and large roundabouts in the greater London area is described. The study was confined to 38 junctions at which roundabouts had been installed between 1970 and 1975, and it compared the accident rates before and after the installation. A significant decrease in the overall accident rate was recorded at all the junctions after roundabouts had been installed, but the main reductions are reported to be in accidents involving pedestrians, fatal or serious injury and those which formerly involved right-turning or cross-flow movements. It is also reported that the percentage reduction in accidents increased with the size of the central island, although raised islands produced a greater improvement than kerbless islands for which nose to tail collisions and accidents involving two-wheeled vehicles increased in number. The author suggests that the installation of mini and small roundabouts could improve safety in accident blackspot sites, and that semi-raised islands are preferable to kerbless islands because they ensure deflection and speed reduction by the smaller, faster, vehicles. /TRRL/

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  • Corporate Authors:

    Printerhall Limited

    29 Newmart Street
    London W1P 3PE,   England 
  • Authors:
    • Lalani, N
  • Publication Date: 1975-12

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Filing Info

  • Accession Number: 00142155
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Analytic
  • Files: ITRD, TRIS
  • Created Date: Aug 4 1977 12:00AM