You already know that to drive safely, you need to be alert, aware and able to make quick decisions. Alcohol alters the normal function of the brain and body, and interferes with your ability to drive safely by impairing your judgment (like figuring out how fast another car is going) and your reaction time (like how quickly you can brake and steer to avoid that car that is going faster than you thought).
In addition to reducing the mind’s alertness, the body’s coordination can be affected as well. Vision may be blurred or doubled. The eyes’ depth perception— which under normal circumstances lets drivers know if objects like other cars or pedestrians are close or far away – is altered in drivers who have been drinking. Think about it: how could someone possibly drive if they can’t tell how close something is or how fast it is going? It’s not hard to understand why drivers who have been drinking cause so many serious accidents.
As we’ve noted, alcohol affects judgment. Ironically, and potentially tragically, people who drive after drinking may feel overconfident and not realize that their driving skills are impaired. Many have been known to say, when their friends are urging them not to get behind the wheel, “I drive better when I’ve had a few drinks.” It’s sad. Their driving is more likely to be careless or reckless than “better” in any way. These people are more likely to weave in and out of lanes, speed excessively, miss stop signs, drive off the road, or make other critical mistakes
If you’re not convinced of the seriousness of impaired driving, here’s a sobering fact: law enforcement tells us that alcohol is involved in about 40 percent of all fatal highway accidents. Here’s another fact: a young driver (that’s you!) with a blood alcohol limit of only .02 to .05 percent is at least seven times more likely to be killed in an accident than a sober driver. A driver with a blood alcohol content of 12 percent is 90 times more likely to be killed. It’s simple: If you drive, don’t drink. If you drink, don’t drive.