There are a number of research tools to support implementation of the HSM, and research underway to advance the use of the HSM.

Science of Safety User Manual Matrix – The matrix includes a comprehensive list of resources a HSM user might need and indicates where this information can be found. Some examples of the resources listed include case studies, crash modification factors, predictive methods, SafetyAnalyst, safety performance functions, etc. Click here for more information.

NCHRP Report 600: Human Factors Guidelines for Road Systems – Explores human factors principles and findings for consideration by highway designers and traffic engineers, and is applicable in Part B of the manual. Click here to access the manual.

A Guide for Developing Quality Crash Modification Factors (CMF) – The guide includes background information on CMFs and the methods for developing them, including an overview of each method, sample size considerations, and strengths and weaknesses. Click here for more information.

Recommended Protocols for Developing Crash Modification Factors (CMF) – This document provides basic knowledge of CMF research for those unfamiliar with the process along with details on how people should document a study to determine a CMF. Click here for more information.

HSM Knowledge Base and Knowledge Base Companion – Details the literature search and research conducted to develop Part D of the HSM. Click here for more information on the Knowledge Base and click here for more information on the Knowledge Base Companion (NCHRP 17-27).

Research Underway

This is a list of current research that will be available in the future to help with implementation of the HSM.

  • Lead State User Guide (NCHRP 17-50) will serve as a companion to the HSM and show practical approaches to implementing HSM procedures in the operating environment of a highway agency.
  • Consideration of Roadside Features in the Highway Safety Manual and the Roadside Design Guide (RDG) (NCHRP 17-54) provides a probability of encroachment model to quantify the safety of a roadside design and compare the design against other designs. Safety Prediction Models for Six-Lane and One-Way Urban and Suburban Arterials (NCHRP 17-58) includes a predictive method for use in the HSM to address crash frequency and severity for both roadway segments and intersections on arterials with six or more lanes and one-way arterial streets.