III. Methodology

A. Statistical Data

Various sources of statistical data and information on safety belt wearing rates and crash data were examined to formulate a concise statement of the problem concerning teens and safety belt use. NHTSA’s National Occupant Protection Usage Survey (NOPUS) was examined for national observational data on teen safety belt use. NHTSA’s Motor Vehicle Occupant Safety Survey (MVOSS) was examined for what teens report as their use in this telephone survey, and also reasons why they do not wear safety belts. The Youth Risk Behavior Surveillance System (YRBSS) survey, conducted by the Centers for Disease Control and Prevention (CDC) via telephone, was used to explore trends of reported use by teens and other related behaviors. NHTSA’s Fatality Analysis Reporting System was analyzed for use in fatal crashes by teens compared to other age groups.

B. Literature Review and Collection of Relevant Information

A comprehensive literature review was conducted, and relevant information and data was collected. The sources for this data collection and literature review are described below.

  1. Interviews
    A project staff member conducted in-person interviews with NHTSA staff at NHTSA offices in Washington, DC. The purpose of these interviews was to identify past or current programs and research deemed relevant to this study, as well as to identify additional sources of information on appropriate projects and research.

    NHTSA staff included representatives from occupant protection programs, alcohol programs, distracted-driver programs, GDL programs, and the research, enforcement, and communication offices. A total of nine NHTSA staffers were interviewed. These interviews provided information that led to interviews with several additional people. A copy of the interview guideline is included as Appendix A.

    2. Literature Reviews
    NHTSA Literature
    Key NHTSA officials were interviewed at their headquarters office to obtain any relevant NHTSA reports on this subject and to gather information on recommended data sources for the review. Each NHTSA Regional Office was contacted to determine the existence and availability of any relevant reports of programs or surveys pertaining to teen safety belt use.

    Program Reports from State Highway Safety Offices
    Potentially, many survey reports (and teen safety belt use programs) at the State level have never been published and do not appear in the formal literature. Therefore the Governor’s Highway Safety Association (GHSA) conducted a short survey of State Highway Safety Offices (SHSOs) to determine if any surveys or reports at the State level on teen safety belt use would be available for review. Similar GHSA surveys in the past47 have been successful using this strategy. Each SHSO was asked about the existence of any surveys, reports, programs, interventions, or strategies dealing with teen safety belt use. Copies of all relevant reports and data were obtained. A copy of the GHSA survey questions is contained in Appendix B. A total of 27 States (plus Guam) responded to this survey. Some provided relevant new reports on the teen safety belt issue.

    Scientific Literature
    A formal literature review was conducted using key words such as teenagers, safety belt use, risky behavior, and motor vehicle crashes. The Dialog databases that were examined are listed in Appendix C. In addition to these, other potential sources of information recommended by NHTSA were examined. These included the following:
    • Indian Health Service
    • American Driver and Traffic Safety Education Association
    • National Indian Education Association
    • Transportation Research Board
    • AAA, formerly known as the American Automobile Association
    • Centers for Disease Control and Prevention
    • Automotive Occupant Restraint Council
    • Traffic Safety Digest (publication of NHTSA)
    • National Organization for Youth Safety
    • Crash Injury Research and Engineering Network
    • National Automotive Sampling System

Safety belt programs that were identified through the literature review and interviews were organized in the following six categories: (1) programs targeted to increase teen safety belt use with some evidence of program effectiveness; (2) programs targeted to increase safety belt use in general with some evidence of effectiveness; (3) programs targeted to increase teen safety belt use - no evidence of effectiveness provided; (4) programs targeted toward other teen health behaviors that could provide insights for teen safety belt interventions; (5) programs to increase safety belt use in general with no evidence of effectiveness; and (6) documents providing evidence that some programs are not effective. In the search for effective teen safety belt programs, the scientific quality of the evaluations were classified under six headings, using the following criteria:

Table 1. Identification of Effective Teen Safety Belt Programs

Evaluation Categories
A. Informative only.
Information on teen safety belt use, e.g., descriptions of the problem, rates, reporting of existing information.
B. Program description only.
It is expected that the majority of program documentation will consist only of the program description with some favorable comments by those involved. Where these are innovative and of particular interest, they may be included in the report, perhaps along with suggestions for what would be needed to evaluate them.
C. Program description with pre-post knowledge/attitude tests.
School programs and those presented to specific groups of teens are likely to be evaluated through pre/post tests. Some of these may strengthen the study by including a control group. However, the major weakness of such evaluations is that such self-reports can overstate actual safety belt wearing rates.
D. Program description with pre/post self-report surveys on safety belt use.
Random telephone surveys provide stronger evidence of the probable impact of a program because the responses are not directly contiguous with the training or the message and because they should better reflect communitywide behavior. However, like all self-report measures, they may overstate use rates.
E. Program description with pre/post observational surveys of safety belt use.
Observational surveys, if properly conducted, provide the best evidence for the effectiveness of safety belt programs, particularly if comparison sites are included. However, increased wearing rates do not necessarily prove that the crash injury rate has been reduced. A special problem for the proposed study is that occupant age must be estimated and, as a practical matter, the age range that can be reliably observed in surveys such as NOPUS is 16 to 24.
F. Program description with pre/post data on safety belt use of occupants involved in crashes and crash severity reduction analysis.
Crash data provide the ultimate evidence of the cost-effectiveness of a safety belt program. However, crash severity is affected [impact is not a verb] by many factors that must be controlled before a change can be attributed to changes in safety belt wearing rates.
Clarity of article (methods clearly identified and explained)
Quality (science-based, data-driven)
Relevance to Teens (behavior change; belt use)
Evidence of Effectiveness (some pre/post analyses)
1-2-sentence description of the study or report.

The following key issues were examined during this review of the studies:

  • the potential for the intervention to reduce the burden of injury or death (due to motor vehicle crashes and nonbelt use);

  • the potential for the intervention to increase healthy behaviors (safety belt use by teens) and reduce unhealthy behaviors (nonuse of safety belts by teens);

  • the potential to phase out widely used but less effective interventions in favor of more effective and or more cost-effective options;

  • the current level of interest among providers and decision makers;

  • the currently accepted models of risk behaviors that are relevant to traffic safety in our population of interest;

  • the potential barriers to buckling up, such as vehicle type, air bag perceptions, seating positions, and comfort