During 2003, an estimated 1.2 million adults aged 21 or older were arrested for driving under the influence (DUI) of alcohol or illicit drugs. DUI arrests were more frequent among younger adult drivers and among male drivers. Among the adult drivers arrested for DUI during 2003, 2.8 percent reported they had been previously arrested for DUI during the past year. 2003 adult DUI arrests were more frequent in the Midwest, South, and West and were less frequent in the Northeast. Differences in DUI adult arrests were also noted by county size, with adult drivers in small metropolitan counties more likely to be arrested for DUI than adult drivers in large metropolitan counties. Figures, endnotes