U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
The AASHTO Highway Safety Manual (HSM), published in 2010, presents for the first time a complete collection of technical knowledge describing the quantitative safety effects – motor vehicle crashes and their outcomes – of actions involving the highway and street environment. The HSM was developed through a 10-year research effort. It was written for use by any transportation professional concerned with highway and traffic safety. The HSM is organized in four parts:
The HSM is a potentially transformative document for Departments of Transportation (DOT) and other agencies responsible for the planning, design, construction, and operation of their highway systems. Under current practices agency actions are based on results from proven, science-based tools to measure or estimate effects of traffic operations, of a myriad environmental factors, and of the many aspects of capital and life-cycle costs. However, no proven and accepted tools or methods for understanding explicit safety effects existed in the past in a central document. With publication of the HSM, DOTs and other agencies now for the first time have access to a proven and science-based means of characterizing the explicit safety effects (i.e., crash frequency and severity) of decisions and actions of an agency.
The mission and vision statements of most DOTs refer directly to safety as a core value. The HSM adds a new dimension to defining and understanding what the term “safety” really means. To fully understand and take advantage of the HSM, DOTs will need to conduct thorough reviews of their organization and management, data systems, program and project development policies and methods, internal training programs, and even culture. Investments in training and technology transfer, and in improved or different data and skills will be needed. An assessment of budgets may be needed.
This guide is intended for managers of DOTs charged with leading and managing agency programs impacting the project development process and safety programs. This guide is based on lessons learned from early adopters of the HSM, many of whom are participating in AASHTO’s Lead State Initiative. It outlines what the HSM is (and is not), how it relates to other core technical documents and policies, and the potential benefits of its use. These benefits can be broadly understood as a means to improve the safety performance of their highway system. In this context the improvement of safety is defined as a reduction in fatalities and injuries. The guide is written in three sections – Introduction to the HSM, HSM Implementation Considerations, and HSM Implementation Opportunities in Program Development and Project Delivery.