RES2020-04: A Localized Safety Performance Functions (SPFs) Approach Accounting for “Within” Tennessee Variations on Freeways & Interchanges

The Tennessee Department of Transportation (TDOT) is in the process of adopting the Highway Safety Manual (HSM) by developing jurisdiction-specific crash prediction models (termed as Safety Performance Functions or SPFs). This report documents the development and implementation of SPFs for three types of rural multilane roadways. It aims to 1) develop Tennessee-specific SPFs for total and fatal/injury (FI) crashes on rural five-lane undivided-with a two-way left-turn lane (5T) segments, 4-lane divided (4D), and 4-lane undivided (4U) roadway segments, 2) compute TN-specific crash modification factors (CMFs) for the key explanatory variables, 3) explore the role of new variables such as speed limit and surrounding land use in SPFs, and 4) prepare new TN-specific prediction tools (spreadsheets) for future use by TDOT. The project required extensive data extraction, integration, and analysis. Specifically, crash, roadway, and traffic data were extracted using various sources and websites maintained by TDOT. Based on the results, this report recommends strategies that can advance the analysis of safety data.

• Record URL:
  • https://www.tn.gov/content/dam/tn/tdot/long-range-planning/research/final-reports/2020-final-reports-and-summaries/RES2020-04_Part2_Final_Report_Approved1.pdf

Language

• English

Project

• Status: Completed
• Funding: $174966
• Contract Numbers:

  RES2020-04

  40100-07219

  60676

• Sponsor Organizations:

  Tennessee Department of Transportation

  James K. Polk Building
  Fifth and Deaderick Street
  Nashville, TN  United States  37243-0349
• Managing Organizations:

  Tennessee Department of Transportation

  James K. Polk Building
  Fifth and Deaderick Street
  Nashville, TN  United States  37243-0349
• Project Managers:

  Jonas-Fields, Stephanie

• Performing Organizations:

  University of Tennessee, Knoxville

  Center for Transportation Research
  Conference Center Building
  Knoxville, TN  United States  37996-4133
• Principal Investigators:

  Khattak, Asad

• Start Date: 20191101
• Expected Completion Date: 20220228
• Actual Completion Date: 0
• USDOT Program: Transportation, Planning, Research, and Development

Subject/Index Terms

• TRT Terms: Crash analysis; Crash rates; Freeways; Highway safety; Interchanges
• Identifier Terms: Safety Performance Functions
• Subject Areas: Highways; Planning and Forecasting; Safety and Human Factors;

Filing Info

• Accession Number: 01744115
• Record Type: Research project
• Source Agency: Tennessee Department of Transportation
• Contract Numbers: RES2020-04, 40100-07219, 60676
• Files: RIP, STATEDOT
• Created Date: Jun 25 2020 5:52PM