You cannot safely operate a motor vehicle while taking recreational or illegal drugs, or even certain prescribed medications, and you cannot safely drive and drink alcohol. Driving while impaired by drugs or alcohol will cost you money, your license, or even your life.

Safe driving requires precise actions, clear judgment, full concentration, and quick and accurate reactions. Drugs, even some prescription drugs, and alcohol, even in small amounts, affect all of these skills and make driving safely impossible.

You must follow any directions on any medication that you have been prescribed; do not drive if your prescription warns against it or causes drowsiness or other impairments.

Remember that the effects of drugs and alcohol vary widely, from person to person, as well as from dose to dose. You may drink less, yet be more impaired than your friend, than guidelines suggest, or even than you were last time, because of all the variables involved in your body’s processing of the substance. If you haven’t eaten, if you are under stress, if you have taken other drugs or medication, if it’s a different time of day—all of these things will change how the drugs you take or alcohol you drink affect you.

With alcohol, for instance, research shows that the average person is actually impaired long before he or she is legally drunk. 

And, do not think a quick cup of coffee or some other caffeinated drink will sober you up. Drugs and alcohol are processed by your body over time; you cannot speed that time up. For instance, it takes about an hour for the average person to process and eliminate two-thirds of the alcohol in a standard drink. If you had 3 drinks in 1 hour, after 3 hours, you’ll still have 1 drink in you!