Research Report
Darren J. Torbic, Daniel J. Cook, Karin M. Bauer, Joseph R. Grotheer, Douglas W. Harwood, Ingrid B. Potts, Richard J. Porter, Jeffrey P. Gooch, Kristin Kersavage, Juan Medina, and Jeffrey Taylor
Jan-21
The first edition of the Highway Safety Manual (HSM) included safety performance functions (SPFs) for roadway segments and intersections. However, not all intersection types are covered in the first edition of the HSM. This research was conducted to develop SPFs for new intersection configurations and traffic control types not covered in the first edition of the HSM, for consideration in the second edition of the HSM. Based on input received through a survey of state and local agencies as well as the research project panel, SPFs were developed for the following general intersection configurations and traffic control types: Rural and urban all-way stop-controlled intersections; Rural three-leg intersections with signal control; Intersections on high-speed urban and suburban arterials (i.e., roadways with speed limits greater than or equal to 50 mph); Urban five-leg intersections with signal control; Three-leg intersections where the through movements make turning maneuvers at the intersections; Crossroad ramp terminals at single-point diamond interchanges; and Crossroad ramp terminals at tight diamond interchanges. The research team coordinated with several state agencies to locate candidate intersections for use in developing the SPFs. Site characteristic data were collected for all candidate intersections to select a final list of sites for model development. In addition, crash and traffic volume data were assembled for model development.
NCHRP Web-Only Document 297: Intersection Crash Prediction Methods for the Highway Safety Manual
Arterial highways
Crash data
Data collection
Diamond interchanges
Ramps (Interchanges)
Rural areas
Signalized intersections
Stop signs
Suburbs
Three leg intersections
Traffic volume
Turning traffic
Unsignalized intersections
Urban areas
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.
