A Primer on Safety Performance Measures for the Transportation Planning Process

Introduction

In 2008 more than 37,000 people were killed and nearly 2.35 million were injured in crashes on the Nation's roadways (Source 1). The consequences of traffic crashes are felt not only by those directly involved but also by family members, friends, and coworkers who must deal with a devastating loss or find resources to cope with disabling injuries. The costs to society such as lost productivity, property damage, medical costs, emergency services, and travel delays are also tremendous.

For these reasons improving safety is one of the primary goals of transportation officials. Years of experience with safety projects and strategies have shown that benefits associated with efforts to improve transportation safety far outweigh the resources consumed.

The most critical safety benefit is a decrease in the number of fatal and injury crashes that occur each year on streets and highways across the Nation. Motor vehicle crashes are the sixth leading cause of death and the leading cause of injuries in the United States. Beyond the pain and suffering of victims and their friends and relatives, these crashes are a significant economic burden to the Nation. In 2004, the American Association of State Highway Officials (AASHTO) estimated traffic crashes in the United States accounted for over $230 billion in economic losses every year (Source 2). Improving safety not only saves lives, but also produces other societal, environmental, and monetary benefits, such as greater mobility, increased economic development, and improved quality of life.

Transportation system improvements are initiated in the transportation planning process. Every urbanized area in the country uses a planning process to identify those transportation system improvements that most effectively address the needs of the community. Consideration of safety issues during the transportation planning process is important to improving transportation safety, as it enables the funding of safety related projects. Proper safety performance measures are key to ensuring that safety issues are considered and addressed throughout the transportation planning process.

One particularly important benefit of performance measures is the information generated through their use over time. Consistent analysis of data reflecting safety performance of the transportation system is particularly important for identifying goals to guide transportation planning efforts and focusing attention and resources on safety-related challenges, as well as monitoring progress toward their achievement. Over the past 15 years, the transportation profession has increasingly used performance measures as the primary mechanism for providing this information. Information collected through the use of safety performance measures are used to prioritize investments, demonstrate progress toward goals in statewide and metropolitan long-range transportation plans, implement statewide and metropolitan transportation improvement programs (S/TIP), and monitor overall system performance. The S/TIP is a resource-constrained program that identifies the projects to be implemented.

This Primer is a tool to help State and local practitioners, transportation planners, and decision-makers identify, select, and use safety performance measures as a part of the transportation planning process. The Primer draws from current literature, professional experience, and State DOT and MPO practice. Key elements of the Primer include the following:

• A definition of performance measures;
• A step-by-step description and flowchart showing how safety performance measures can be identified and integrated into the transportation planning process;
• Characteristics of effective performance measures;
• A checklist to assess an organization's current status with respect to the use of safety performance measures in the transportation planning and decision-making process;
• A list of references; and
• Case studies of noteworthy practice.