As mentioned before, the effects of alcohol on driving depends on many different factors  (food you’ve eaten or medication you’ve taken, mental state, degree of fatigue, strength  of drinks). Therefore, it is difficult to know just how much you can drink before you drive  It takes an average of one hour to cancel the effects of one drink. Therefore, it takes about  four hours to cancel the intoxicating effects of four drinks. THE BEST POLICY IS TO NOT  DRIVE IF YOU HAVE BEEN DRINKING.  KNOW YOUR LIMITS FACTS YOU SHOULD KNOW ABOUT ALCOHOL: 1. A person’s judgment is the first ability impaired by drinking alcohol. 2. Alcohol is a depressant, not a stimulant. It slows normal reflexes, interferes with judgment, reduces alertness, and impairs vision. 3. If you drive after drinking, the probability of a crash increases with each drink. 4. Motor vehicle crashes involving young people who have been drinking occur at lower average blood alcohol levels than do those of middle-aged or older drivers. 5. The type of alcohol consumed makes no difference in the effect of alcohol on the physical and mental changes that take place within the body when alcohol is consumed. It’s the amount of alcohol which enters the body that counts. The 6. Alcohol affects a person differently at different times. Physical and emotional condition, other drugs, even the amount of food in the stomach causes alcohol to affect a person differently. 7. After drinking there is nothing you can do but wait. Black coffee, fresh air, food, or a cold shower might wake you up, but they won’t sober you up. Alcohol is burned up by the liver and eliminated from the body through the kidneys and lungs. Only time will help. 8. Alcohol is medically termed a drug and a depressant. The combined use of alcohol and other drugs may be more dangerous to health and to highway safety than the effects of either the alcohol or drugs alone. same amount of alcohol is present in 12 ounces of beer as in a single shot (1 1/2 ounce) of 80 proof alcohol or 4 ounces of wine.