Safety Performance Functions for Florida's Freeways

Safety performance functions (SPFs) are a required input to the newly released SafetyAnalyst software tool. Using statistical goodness-of-fit measures and visual plots, this paper compares the performance of locally calibrated SPFs using Florida data with the default SPFs from SafetyAnalyst for both freeway interchange influence areas and basic freeway segments. SafetyAnalyst defines an interchange influence area as one that extends 0.3 miles upstream and 0.3 miles downstream of the respective gore point. Using four years of local crash data (2007-2010) from Florida, SPFs for both types of segments for both urban and rural areas were developed using the negative binomial (NB) regression model. The results showed that Florida-specific SPFs generally produced better-fitted models than the calibrated SafetyAnalyst-default SPFs. This was clear in that the majority of Florida-specific models had higher Freeman-Tukey R-square (R2FT), as well as lower mean absolute deviance (MAD) and mean square prediction error (MSPE) estimates.

• Record URL:
  https://doi.org/10.1061/9780784413586.031
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/9780784413586
• Supplemental Notes:
  • © 2014 American Society of Civil Engineers.
• Corporate Authors:

  American Society of Civil Engineers

  1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400
• Authors:
  • Lu, J
  • Haleem, K
  • Gan, A
  • Alluri, P
• Conference:
  • Second Transportation & Development Congress 2014
  • Location: Orlando Florida, United States
  • Date: 2014-6-8 to 2014-6-11
• Publication Date: 2014-5

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: pp 321-331
• Monograph Title: T&DI Congress 2014: Planes, Trains, and Automobiles

Subject/Index Terms

• TRT Terms: Calibration; Crash risk forecasting; Freeways; Interchanges
• Identifier Terms: Safety Performance Functions; SafetyAnalyst (Software)
• Geographic Terms: Florida
• Subject Areas: Highways; Safety and Human Factors; I82: Accidents and Transport Infrastructure;

Filing Info

• Accession Number: 01531688
• Record Type: Publication
• ISBN: 9780784413586
• Files: TRIS, ASCE
• Created Date: Jul 25 2014 4:20PM