A Semiparametric Statistical Approach to Evaluate Conflict Severity As a Surrogate for Crashes in the Context Of Pedestrian Safety

There is growing interest among traffic engineers for using so-called surrogate measures of safety as an alternative to crash counts, especially in contexts where the temporal and/or spatial crash occurrence rate is extremely low. In order to facilitate this paradigm shift, it is useful to demonstrate significant association between conflicts and crashes, and to study how this association might vary by location. The authors investigate a semiparametric statistical approach called the tau-path method that enables us to rank locations by decreasing magnitude of the association between crash and conflict counts. The authors demonstrate the method in the context of pedestrian safety at intersections in central Connecticut with variation in several characteristics including crossing distance, pedestrian signal phasing type, presence or absence of on-street parking and surrounding land use. Locations with high association between conflicts and crashes were more likely to have exclusive pedestrian phasing and on-street parking. Among these locations, those with high conflict and crash counts were more likely to have on-street parking and be in non-residential areas. The tau-path method can be easily applied to other road safety contexts beyond investigating conflict counts as surrogates for crash counts. This approach is also relevant to more general data mining settings where there is a need to identify a subpopulation in which there is a strong association between a pair of variables of interest.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee ABJ80 Standing Committee on Statistical Methods.
  • Corporate Authors:

    Transportation Research Board

    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Authors:
    • Zhang, Yaohua
    • Ravishanker, Nalini
    • Ivan, John N
    • Mamun, Sha A
  • Conference:
  • Date: 2017


  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 20p
  • Monograph Title: TRB 96th Annual Meeting Compendium of Papers

Subject/Index Terms

Filing Info

  • Accession Number: 01624332
  • Record Type: Publication
  • Report/Paper Numbers: 17-02090
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 8 2016 10:45AM