• Development of Safety Benefit Factors for New Location and Widening Projects for Use in the STI Scoring Process

    NCDOT Research Project Number: 2020-26

 Executive Summary

  • Safety is a key component of the project scoring process conducted by NCDOT as part of the 2013 Strategic Transportation Investments (STI) law. For most improvement types in the STI process, Safety Benefit Factors (SBFs) are used to quantify the benefits expected from a reduction in crashes stemming from a given project. 

    This study fills a gap that currently exists in the safety component of the STI process and enhancing the current state of knowledge on how new location projects (e.g. bypass, road extensions, etc.) and widening projects (e.g. rural and urban areas, widening to multi-lane divided facility, etc.) can impact safety. Taking into account the limited amount of data available at the time projects are scored, the research team developed SBFs and guidance that can be easily integrated into the current scoring process. Consistent with NCDOT’s method of selecting SBFs, the research team focused on incorporating practices from the Highway Safety Manual (HSM) as well as existing crash modification factors (CMF) knowledge from research studies. 

    2020-26 Picture.jpg

    In total, this study resulted in the generation of 10 new SBFs for NCDOT and the confirmation of 2 SBFs already utilized by NCDOT, as outlined in the following table. Additionally, approaches for developing SBFs using North Carolina project and crash data were also developed through this research. 

    These findings and approaches can be used by NCDOT into the future to develop more reliable estimations of safety benefits for proposed projects, and ultimately improve the quality of North Carolina transportation projects developed in the future

Joy C. Davis
Joy C. Davis; Daniel Findley; Raghavan Srinivasan; Taha Saleem; Nick Norboge
Brian Murphy
Mustan Kadibhai, PE, CPM
NC State University - ITRE
UNC Chapel Hill - HSRC

 Report Period

  • August 1, 2019 – January 31, 2022


  • Complete


  • Traffic, Mobility, Safety and Roadway Design

 Sub Category

  • Traffic Safety

 Related Links

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