This study assessed whether persons who begin drinking at younger ages are more likely to report drunk driving and alcohol-related crash involvement over the life course, even after controlling analytically for diagnosis of alcohol dependence, years of drinking alcohol, and other personal characteristics associated with the age respondents started drinking. A national survey asked 42,862 respondents the age that they started drinking, whether they drove after drinking too much, and whether they were in motor-vehicle crashes because of their drinking. This analysis focused on 27,081 (65%), who reported ever drinking in their lifetime. The earlier the age respondents started drinking, the more likely they were to report driving after drinking too much and being in a motor-vehicle crash because of their drinking even after adjusting for current/ever diagnosis of alcohol dependence, number of years respondents had been drinking, and other characteristics and behaviors associated with the age respondents started drinking. Particularly, among persons who were never alcohol-dependent, those who began drinking in each age group under 21, relative to those starting at age 21 or older, were more likely to report "ever" and "in the past year" being in a crash after drinking too much. The traffic safety benefits of delaying drinking may extend well beyond the legal drinking age of 21.