Highway Safety Manual

About the Highway Safety Manual

The Highway Safety Manual (HSM) provides methods for quantifying highway safety performance. It includes guidance on: human factors and the fundamentals of traffic safety, the roadway safety management process, predictive methods for road safety evaluations, and the associated impact of the potential effects of design alternatives or changes from base conditions.

The Highway Safety Manual (HSM) is the pioneer guidance document for incorporating quantitative safety analysis in the highway transportation project planning and development processes, published in 2010 with a supplement for freeways published in 2014. The HSM included over 15 years of research in road safety.

2nd Edition of HSM

National Cooperative on Highway Research Program (NCHRP) Project Number 17-71 aims to develop and prepare a proposed HSM 2 in a format suitable for adoption, updating the manual and incorporating state-of-the-art research, lessons learned, and more. The 2nd Edition of HSM is expected to be completed in 2024, being published by AASHTO.

To access the current edition of Highway Safety Manual (HSM) please click here.