Publication Details

Development of safety benefit factors for new location and widening projects for use int he STI scoring process

Type: Paper

Subtype: Final report

Author(s): Davis, Joy C.; Saleem, Taha; Srinivasan, Raghavan; Findley, Daniel J.; Norbage, Nicolas

Publisher: North Carolina Department of Transportation


Publication Date: Oct-2021

Number: FHWA/NC/2020-26

Address: Raleigh, NC

Abstract: Safety is a key component of the project scoring process conducted by NCDOT as part of the Strategic Transportation Investments (STI) law. For all highway 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. SBFs are designed to estimate the safety benefits that can be expected with the implementation of a specific project type with particular characteristics. While NCDOT utilizes evidence-based SBFs for numerous project types, the agency lacks SBFs for some types of projects because data needed to make reliable estimates of crash reductions is not always readily available at the time projects are being scored. Additionally, safety research on certain types of projects can be limited or unavailable. 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 (eg bypass, road extensions, etc.) and widening projects (eg rural and urban areas, widening to multi-lane divided facility, etc.) can impact safety. Evidence-based safety research for new location and widening projects is limited, which makes evaluating the impact of such projects difficult. Consequently, this research focuses on developing evidence-based SBFs for these types of projects to enhance and increase the accuracy of safety estimates in the STI process.