Highway Safety Manual

The American Association of State Highway Transportation Officials' Highway Safety Manual was developed to help measurably reduce the frequency and severity of crashes on highways by providing tools for considering safety in the planning and project development processes.

This manual assists transportation engineers in:

Selecting countermeasures and prioritizing projects,
Comparing alternatives, and
Quantifying and predicting the safety performance of roadway elements considered in planning, design, construction, maintenance and operation.

Oregon Application of the Highway Safety Manual

Unlike other engineering standard documents, the Highway Safety Manual is not formally adopted by a state. The manual does not establish a legal standard of care for highway safety. Rather it should be implemented with other highway safety policies of the state or local jurisdiction.

The Oregon Department of Transportation has evaluated the concepts included in the Highway Safety Manual and initiated activities related to the ideas presented in the manual.

The greatest barrier to implementing Highway Safety Manual concepts is the need for better crash and road inventory data that can easily integrate into associated tools, providing system-wide highway safety analysis. Much of the research activities and discussions in which ODOT is engaged center on these issues.

"Calibrating the Future Highway Safety Manual Predictive Methods for Oregon State Highways," Feb. 2012 - SPR 684 OTREC-RR-12-02

Oregon State University and Portland State University completed a research study to develop calibration factors for Oregon to better apply the predictive methods found in the HSM.

Calibrating the manual's methodologies is a key step to implementing various parts of the HSM in Oregon.

Data Needs Assessment for Part B of the Highway Safety Manual

Oregon State University conducted an additional study to assess the deficiencies in Oregon's crash and roadway inventory data to fully implement the methodologies found in Part B of the Highway Safety Manual.

TPF-5(255) Highway Safety Manual Implementation Multi-state Study

ODOT is participating with 14 other states and FHWA in a pool-funded study to evaluate implementation strategies, successes and trials related to implementation of concepts identified in the Highway Safety Manual.

The Safety Investigations Manual is a resource for ODOT traffic investigators with highway safety project screening and evaluations. It contains some Highway Safety Manual concepts and is a good resource for practitioners who regularly investigate highway safety issues and perform highway safety assessments.

"Improved Safety Performance Functions for Signalized Intersections" - Texas A&M Transportation Institute and Portland State University for ODOT and FHWA, Report SPR 756, August 2015.

"Validation of Models for Quantifying Safety Performance of Driveways on State Highways" - Texas A&M Transportation Institute for ODOT, June 2014

"Developing Safety Performance Measures for Roundabout Applications in the State of Oregon" - Oregon State University for ODOT and FHWA, Report SPR 733, April 2013

"Assessment of Statewide Intersection Safety Performance" - Portland State University, Oregon State University and CH2M Hill for ODOT and FHWA Report SPR 667, June 2011

Related Tools

Several training opportunities are available for those interested in learning more about the Highway Safety Manual and how to use the methodologies it describes.

AASHTO's Highway Safety Manual website includes online training guides.
Oregon State University's Kiewit Center for Infrastructure and Transportation offers several continuing education workshops about highway safety annually.
National Highway Institute

Generic HSM Spreadsheets - These free spreadsheets are available to download from the AASHTO Highway Safety Manual website.

Oregon HSM Spreadsheets with local crash data from 2004-2006 - See the Segment and Intersection tables for locally-derived values and consult the HSM Calibration for Oregon Report for explanation of these values. Locally-derived values are enabled by default.

Rural two-lane highways
Rural multi-lane highways

There are no local values for four-leg signalized intersections.

Urban and Suburban arterials

There are no local values for Table 12-21.

Crash Modification Factors Clearinghouse - This is a free companion tool to the HSM Part D Crash Modification Factors, funded by FHWA and maintained by the University of North Carolina Highway Safety Research Center.

PLANSAFE - Planning-level safety forecasting tool is provided free by the Transportation Research Board, and developed as part of the National Cooperative Highway Research Program Project 08-44.

Interactive Highway Safety Design Model - This is a free companion tool to the HSM Part C Predictive Methods Section, provides detailed analysis for the predictive method. It is maintained by the Turner-Fairbank Highway Research Center of the FHWA.

HiSafe - This is a companion tool for Part C of the manual. Digiwest offers a free trial period, after which a licenses for use starts at $500.

AASHTOWare Safety Analyst - This is a companion tool for Part B of the manual, available from AASHTO, under the AASHTOWare licensing program. This is NOT a free tool.