As an increasing number of motorways with two-lanes in each direction are being fitted with a third lane, this study examines whether the occurrence of accidents is thereby influenced. It was established, that the left hand lane exhibited an exceptionally high accident rate and accident cost rate in comparison to the middle lane, the latter having an accident rate and accident cost rate only half as high. In spite of its low accident rate, the right hand lane did have a high accident cost rate due to major damage to lorries, which generally use this lane. Each lane has its own characteristic accidents, thus the cause of accidents in the left hand lane, which is used almost exclusively by high speed cars, is traffic congestion in 50% of all cases. On the middle lane with lower velocities and a higher proportion of lorries, the causes of accidents are evenly divided between traffic congestion, lane changing and driving error. On the right hand lane, the main accidents are due to driving error, lane changing, and suchlike. The types of accident were also examined with respect to the type of vehicles involved. It was shown, that for cars driving errors and congestion were the most common causes. In addition it was established that the severity of accidents was particularly high in darkness. A further cause of accidents was also established: that accidents occur on the transition from three to two lanes. There were mainly lane changing accidents. /TRRL/

  • Corporate Authors:

    Technical University of Karlsruhe, West Germany

    Kaiserstrasse 12
    D-7500 Karlsruhe,   Germany 
  • Authors:
    • Kloeckner, J H
  • Publication Date: 1975


  • German

Media Info

  • Features: Figures; Tables;
  • Pagination: p. 58-74

Subject/Index Terms

Filing Info

  • Accession Number: 00157399
  • Record Type: Publication
  • Source Agency: Federal Institute of Road Research, Germany
  • Report/Paper Numbers: Publ. No. 14 Analytic
  • Files: ITRD, TRIS
  • Created Date: Oct 29 1977 12:00AM