Crash Estimation at Signalized Intersections: Significant Factors and Temporal Effect

Longitudinal intersection crash data are observations on a cross section of intersections that are observed over several time periods. Such cross-section and time series data structures have positive temporal correlation within each intersection. Using the basic negative binomial regression leads to invalid statistical inference due to incorrect test statistics and standard errors that are based on the misspecified variance. Generalized estimating equations (GEEs) provide an extension of generalized linear models to the analysis of longitudinal data, which account for the correlation in the repeated observations for a given intersection. In this study, the GEE procedure was used to model the temporal correlation for longitudinal intersection crash data. This analysis was based on 3-year data for 208 four-legged signalized intersections in central Florida. Intersection crash frequencies were fitted through use of GEEs with a negative binomial link function for four correlation structures. Both the functional form and the link function of GEE models were assessed with the cumulative residuals method. This method showed that the total average daily traffic per lane was the best representation of traffic volume, and the GEE model with autoregression structure had the best model performance. Variable relative effect analysis identified the relative effect for the variables in the models. Intersections with heavy traffic, a larger total number of lanes, a large number of phases per cycle, and high speed limits and those in high population areas were correlated with high crash frequencies. The intersections with more exclusive right-turn lanes and with a partial left-turn protection phase had lower crash risks.

• Record URL:
  • https://doi.org/10.3141/1953-02
• 
• Summary URL:
  • http://scholar.google.com/scholar_lookup?title=Crash+Estimation+at+Signalized+Intersections%3a+Significant+Factors+and+Temporal+Effect&author=X.+Wang&author=M.+Abdel-Aty&author=P.+Brady&publication_year=2006
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309099625
• Authors:
  • Wang, Xuesong
  • Abdel-Aty, Mohamed
  • Brady, Patrick A
• Publication Date: 2006

Language

• English

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 10-20
• Monograph Title: Safety Data, Analysis, and Evaluation
• Serial:
  • Transportation Research Record: Journal of the Transportation Research Board
  • Issue Number: 1953
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Average daily traffic; Crash rates; Crash risk forecasting; Longitudinal studies; Mathematical models; Regression analysis; Signalized intersections; Traffic volume
• Uncontrolled Terms: Autoregressive models; Generalized estimating equations
• Subject Areas: Data and Information Technology; Highways; Safety and Human Factors; I82: Accidents and Transport Infrastructure;

Filing Info

• Accession Number: 01024838
• Record Type: Publication
• ISBN: 0309099625
• Files: TRIS, TRB, ATRI
• Created Date: May 31 2006 7:55AM