Drunk driving carelessly and needlessly kills and serious injures people everyday. Too many people get hurt by drunk drivers. Of course, a major problem is that people oftentimes do not realize that they are driving while impaired. It is not unusual for me to take the deposition of a drunk driver and for the drunk driver to tell me that he/she thought his judgment was fine.
Alcohol decreases a person's ability to drive a motor vehicle safely. The more someone drinks, the greater the effect. The amount of alcohol required to become impaired differs according to how fast a person drinks, their weight, gender, and how much food they've eaten. Because of these variables, the safest choice is always not to drink and drive.
Mothers Against Drunk Driving has an excellent chart on its website regarding what effects certain levels of alcohol have on a person's ability to drive. http://www.madd.org/drunk-driving/understanding-08.html
I applaud MADD and the efforts it has taken to stop drunk driving. I know through their efforts they have prevented many wrongful deaths and catastrophic injuries caused by drunk drivers.