Highway Safety Manual
The Highway Safety Manual (HSM), published by the American Association of State Highway Transportation Officials (AASHTO) is the recognized source of information and methods for quantitatively evaluating traffic safety performance on existing or proposed roadways. The HSM provides a science-based, technical approach that helps State and local agencies take the guesswork out of safety analysis. FHWA has developed supporting implementation tools including the Interactive Highway Safety Design Model (IHSDM), the Crash Modification Factors (CMF) Clearinghouse, and the Systemic Safety Project Selection Tool. These tools will greatly advance state and local highway agencies' ability to incorporate explicit, quantitative consideration of safety into their planning and project development decision making.
The HSM provides a science-based, technical approach to facilitate consideration of safety in roadway planning, design, operations, and maintenance decisions. This allows safety to be quantitatively evaluated alongside other transportation performance measures such as traffic operations, environmental impacts, pavement durability, and construction costs.
Visit AASHTO's Highway Safety Manual Webpage at highwaysafetymanual.org.
This serves as the official HSM website where you can find the most up-to-date information and new developments on the HSM.
HSM Outreach Materials
HSM Technical Support
- Post questions to HSM User Discussion Forum
- Email questions to firstname.lastname@example.org
HSM Informational Resources
- Safety Analysis Needs Assessment for Transporation Systems Management and Operations
The Federal Highway Administration recently released a conducted a Safety Analysis Needs Assessment for Transportation Systems Management and Operations, intended for transportation practitioners as well as researchers. The needs assessment contains various types of safety performance evaluations for some TSMO strategies. However, there are only a limited number of published safety performance evaluations that are robust enough to inform future evaluations and/or the development of quantitative safety performance predictions. There is a need for safety and operations staff from local, State, and Federal agencies, as well as researchers and other stakeholders, to engage in regular dialog on safety performance evaluation needs and priorities specific to TSMO strategies. The needs assessment also identified methodological needs for analyzing the safety performance of TSMO. The report concludes with recommended next steps in continuing to advance safety performance analysis capabilities of TSMO. Readers of this report will gain an increased understanding of existing knowledge, analysis methods, and research needs in the context of quantifying the safety performance effects of TSMO.
- HSM Implementation Guide for Managers
- Integrating the HSM into the Highway Project Development Process
- Scale and Scope of Safety Assessment Methods in the Project Development Process
The Federal Highway Administration recently released Scale and Scope of Safety Assessment Methods in the Project Development Process, an informational guide that assists State and local agencies in identifying and applying suitable methods for quantitatively assessing the safety performance impacts of project development decisions such as comparing various design alternatives. The guide suggests assessment methods that may be suitable for answering safety performance-related questions that typically arise during each phase of the development process and for projects of various types. It also provides examples that illustrate the thought process for selecting a safety assessment method. This information on safety performance can then be considered in concert with other project criteria to make more informed highway investment decisions.
- State Policies and Procedures on Use of the Highway Safety Manual
The Federal Highway Administration (FHWA) recently released State Policies and Procedures on the Use of the Highway Safety Manual (HSM), an informational report for States developing policies and procedures on use of the HSM in transportation planning and programming, engineering and design, operations and maintenance, and roadway safety management. The report provides noteworthy examples of existing language in States’ policy documents and procedures manuals as well as sample policy and procedures language. The HSM provides methods for estimating safety performance that help practitioners, managers, and executives effectively implement strategies to reduce the number and severity of traffic crashes.
You can find additional FHWA information resources to help implement the HSM at the Roadway Safety Data Program. FHWA's Every Day Counts Data-Driven Safety Analysis Initiative offers State and local agencies technical assistance and training in implementing the HSM; for additional information.
- FHWA HSM Training Courses
- Predictive method (video)
- Observed, Expected Predicted Crashes (video)
- Application of CMFs (video)
- Selecting a Method to Analyze Multiple CMFs (video)
- Applying a Method to Analyze Multiple CMFs (video)
HSM Case Studies
HSM Related Tools
FHWA is promoting tools such as the HSM as part of its Every Day Counts Initiative: Data-Driven Safety Analysis.
- AASHTOWare Safety Analyst™ implements many of the roadway safety management procedures included in Part B of the HSM.
- Spreadsheet Tools, including the Enhanced Interchange Safety Analysis Tool (ISATe) can be used to implement predictive methods found in Part C of the HSM for project specific designs.
- Interactive Highway Safety Design Model (IHSDM) implements predictive methods found in Part C of the HSM for project specific designs. The FREE software provides a visual user interface, graphical output, and the ability import computer aided drafting (CAD) files.
- Crash Modification Factors (CMF) Clearinghouse houses a web-based database of CMFs along with supporting documentation to help transportation engineers identify the most appropriate countermeasure for their safety needs.
- Additional HSM Related Tools
*Disclaimer: FHWA cities specific tools as examples, not as an endorsement of these tools over others.
- HSM Information Contacts
Resource Contact Info AASHTO HSM Information
Kelly Hardy, AASHTO
FHWA Information, Support, and Technical Assistance
FHWA – Office of Safety
FHWA Resource Center
Safety and Design Team
NHI Training Information
Tom Elliott, FHWA-NHI
AASHTOWare Safety Analyst™ Information
Vicki Schofield, AASHTO
CMF Clearinghouse Information
Karen Scurry, FHWA - Office of Safety
Future HSM Development and Feedback
Mark Bush, TRB