The percentage of drivers on the road who are impaired by alcohol has plunged during recent decades, but the percentage of alcohol-impaired drivers in fatal crashes has stayed relatively constant. This disconnect has perplexed researchers and policy experts alike. Characteristics of impaired drivers, such as their tendency not to buckle up, may offer clues to this puzzle and hint at potential countermeasures. Searching for possible explanations, Institute researchers recently compared results of national roadside breath-test surveys conducted on Friday and Saturday late nights in 48 states in 1986, 1996 and 2007 with corresponding data on fatal crashes and driver alcohol use from the U.S. government’s Fatality Analysis Reporting System (FARS).