• April 22nd, 2021

The first edition of the HSM included safety performance functions (SPFs) for roadway segments and intersections. However, not all intersection types are covered in the first edition of tthe 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
  • 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.

Read the full report here.