Turner-Fairbank Highway Research Center

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Rural Speed Safety Project for USDOT Safety Data Initiative

Product Type

Research Report


Subasish Das, Srinivas Geedipally, Raul Avelar, Lingtao Wu, Kay Fitzpatrick, MohamadrezaBanihashemi, and Dominique Lord




The objective of this project was to examine prevailing operating speeds on a large scale to determine how speed and speed differentials interact with roadway characteristics to influence the likelihood of crashes. The project team conducted three major tasks: (a) developed conflated databases for Ohio and Washington by incorporating the Highway Safety Information System(HSIS) and the National Performance Management Research Data Set; (b) developed static and interactive data visualization tools to show the association between operating speed measures and safety outcomes; and (c) developed best-fit models at annual and daily levels to address the impact of operating speed on safety. The overall finding was that speed-related operational information is an area of opportunity to better understand safety outcomes. This pilot project established the framework of data conflation and an analytical pipeline that will help to address the effect of operation speed measures on safety. The replicability procedure developed in this study can be applied to other HSIS States. The project team developed a weblink that includes descriptive statistics and data visualization tools (both static and interactive). The links provide a more detailed view of the speed measures and descriptive statistics, as well as visualization of the association between speed measures and crashes at a granular level. The team members also developed an interactive decision support tool (https://ruralspeedsafety.shinyapps.io/rss_sdi/) to show annual risk scoring using Washington and Ohio data that contain expected total crashes from the developed models.

Link To Research Report

Link not available.


Rural roadways
traffic crashes
operating speed
roadway characteristics
safety performance functions

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HSIS Summaries

HSIS Summary Reports are two to eight pages in length and include a brief description of the issue addressed, data used, methodology applied, significant results, and practical implications.

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Research Reports

A variety of research studies have been performed using data from HSIS. Many of the final reports prepared are now available electronically.

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Technical Summaries

Research reports are often summarized in executive summaries, technical briefs, or other abbreviated formats. Included here are those road safety summaries that involved research using HSIS data.

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Safety Analysis Tools

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