Research Report
Taha Saleem, Richard Porter, Raghavan Srinivasan, Daniel Carter, Scott Himes, and Thanh Le
Nov-20
The main goal of this project was to identify focus crash and facility types (FCFTs) and associated contributing factors to better inform applications of systemic safety improvements. The selection of FCFTs was guided by the use of the Fatality Analysis Reporting System and the Highway Safety Information System (HSIS) databases (NHTSA 2018a; FHWA 2018c). The method used to select potential FCFTs was based on the number of fatal crashes and number of fatal-plus-incapacitating-injury crashes associated with various crash-related variables. A total of 17 FCFTs (8 intersection FCFTs and 9 nonintersection FCFTs) were identified for analysis to identify contributing factors. Three data sources were used to conduct the contributing-factor analysis: crash and roadway inventory from HSIS, climate data from the National Oceanic and Atmospheric Administration, and socioeconomic census data from the U.S. Census Bureau (FHWA 2018c; NOAA 2018; U.S. Census Bureau 2018). For the analysis, the research team used the random-forest method to identify the most predictive variables and then created plots of random forest–predicted crash frequencies as a function of the predictor variables to observe the general trends in the relationships. The research laid out a process for identifying and selecting countermeasures for focus crash types based on contributing factors. The countermeasure guidance focused on traffic and roadway findings. Findings linked to socioeconomic- and weather-related factors showed promise, but there is not yet a significant amount of theory to support or refute the socioeconomic- and weather-related results of this effort.
Contributing Factors for Focus Crash and Facility Types
Systemic safety
focus crash types
contributing factors
random forests
crash prediction
proven countermeasures
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.
A variety of research studies have been performed using data from HSIS. Many of the final reports prepared are now available electronically.
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.
In addition to conducting research, HSIS resources are also used to develop products that can be used by practitioners in the analysis of safety problems.
HSIS data are sometimes used in research studies that result in other types of finished products, such as dissertations, theses, and conference proceedings.
