How DUI Works

Image Gallery: Car Safety A police officer conducts a field sobriety test at a DUI traffic checkpoint. See more car safety pictures.
Image Gallery: Car Safety A police officer conducts a field sobriety test at a DUI traffic checkpoint. See more car safety pictures.
Joe Raedle/Getty Images

Driving Under the Influence (DUI) is one of the biggest dangers facing motorists today. In 2003, 1.4 million Americans were arrested for DUI, and alcohol-related crashes produce an estimated $45 billion in damages every year. On average, a person is injured in an alcohol-related car accident every 30 seconds [ref]. From 2000 through 2005, 103,213 people were killed in alcohol-related car accidents in the U.S., according to Mothers Against Drunk Driving (MADD), a prominent anti-drunk driving advocacy group.

Some of these statistics may be slightly misleading. MADD classifies any accident in which a driver had consumed alcohol as “alcohol-related” -- even if that driver is not deemed responsible for the accident. For example, someone who drank a beer at dinner and is later hit while pulling into a parking spot may be considered part of an “alcohol-related” accident. Sometimes, pedestrians who have consumed alcohol and are struck by a car are classified as being part of an “alcohol-related” accident, even if the pedestrians weren’t intoxicated or at fault [ref]. Even so, MADD’s numbers do speak to a major problem. One study of fatally injured drivers in several states found that 68 percent of sober drivers and 94 percent of intoxicated drivers were responsible for their accidents [ref]. What this means is that driving while intoxicated significantly increases the risk of getting into an accident. In fact, if a driver’s Blood Alcohol Content (BAC) is 0.15 or higher, he or she is 300 times more likely to get into a fatal car accident [ref].


It’s not just alcohol. In one study published in the New England Journal of Medicine, 45 percent of people stopped by police for reckless driving tested positive for marijuana and 25 percent tested positive for cocaine [ref]. Lack of sleep and stimulants are also dangerous. The impairment caused by a lack of sleep c­an be as significant as being legally drunk. Also, recent studies have shown that talking on a cell phone while driving is as dangerous as driving drunk [ref].

For a long time, the federal government and interest groups have been working to educate people about the dangers of drunk driving. Fortunately, there are many ways to avoid DUI. For example, you can watch what you drink, use a designated driver and -- this one’s pretty obvious -- don’t drink before driving.

In this article, we’ll learn about preventing DUI, how a DUI arrest works, and what the punishment is for a DUI conviction. We’ll also expose some common myths about breathalyzers and alcohol. And though some states use terms like DWI (Driving While Intoxicated) or OMVI (Operating a Motor Vehicle While Intoxicated), for this article, we’ll stick to the term DUI.