Background Impaired driving has been a principal culprit in fatal motor vehicle crashes. During the past two decades, tireless efforts were made through national movements toward legislative enactments (blood alcohol concentration (BAC) laws, administrative licensing revocation (ALR) laws, legal drinking age laws, etc.) to deter impaired driving. In addition, many programs that were funded by the States or by the local community chapters were created to reduce the impaired driving rate. As a result, involvement of impaired drivers in fatal crashes has decreased at a steady rate from 57 percent in 1982 to an all time low of 41 percent in 1994. However, it then leveled off and has remained close to 41 percent since 1994.

Objectives Statistically analyze national trends on alcohol involved crashes and alcohol related traffic stops since 1982, taking into account a wide variety of demographic and economic factors as well as alcohol consumption and programs to reduce impaired driving. Study the relationships between impaired driving trends and population by age group and vehicle type (e.g., motorcycles vs. other passenger vehicles). Examine the effectiveness of deterrence programs such as public information and education, legislation (BAC laws, ALR law, etc.), enforcement, prosecution, and adjudication. Identify other external factors (liquor taxes, etc.) that may contribute to the trends and estimate their impact.

Proposed Approach FARS data will be analyzed on a time series and cross-sectional basis (State-by-State). Economic and demographic factors will be compiled from government sources such as NASS reports and State data. Information on State legislative enactment/effective dates and other program activities are available from NHTSA files. Completion of the statistical analyses is expected in 2004.