A Surrogate Safety Analysis at Protected Freeway Ramps Using Cross-sectional and Before-After Video Data

This study presents a surrogate approach for safety analysis of freeway facilities using automated trajectory collection and behavioral analysis from surrogate measures of safety (in particular time to collision). This methodology is proposed as a potential alternative or complement to the classical approach based on historical accident data, particularly suited for evaluating the microscopic safety effects of road treatments for which there is a lack of traffic and accident data. A short theoretical discussion of traffic conflicts is followed by a proposed methodology illustrated using as a small sample of freeway ramps as an application environment. From this sample, video data is obtained as part of a safety study to investigate the effectiveness of the “one-way lane-change ban” treatment near urban freeway ramps in Montreal, Canada. To illustrate the applicability of our methodology, two comparative examples are presented: (1) a cross-sectional study and (2) a before-after study involving two sites, one of which had video data available before and after the implementation of the treatment. Various methods of aggregating the data, spatially and temporally, are explored in the applications.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 17p
  • Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01373555
  • Record Type: Publication
  • Report/Paper Numbers: 12-2955
  • Files: TRIS, TRB
  • Created Date: Jun 25 2012 9:26AM