Physical fitness is a key to safe driving. Let someone else take the wheel if you are not physically or mentally alert. Alcohol and other drugs affect your ability to drive. Millions of people take drugs every day and don’t realize these drugs can affect their driving. Alcohol, tranquilizers, marijuana or any other mind-altering drug, can affect the mental and physical skills needed to drive. Even some over-the-counter medicines can affect driving skills. Different people’s driving skills can be affected differently by the same drug. The driver’s weight and emotional state, the amount of the drug and when it was taken all influence the driver’s ability to size up an emergency situation or to judge speed or distance. Taking more than one drug at the same time can be especially dangerous because each can add to the impact of the other. This is especially true when one of the drugs is alcohol. Research has shown that even typical social doses of marijuana can affect concentration, judgment, and the sensory and perceptual skills needed for careful driving. People who are under the influence of marijuana have impaired sensory and perceptual abilities. While heavy amphetamine use will keep drivers awake and active for long stretches of time, it will also make less coordinated, edgy and as one accident study found, four times more likely to be involved in a car crash. Small amounts of cocaine can produce lapses in attention and concentration. Although caffeine can help the drowsy driver stay alert, it can’t make the drunk driver sober. Ordinary amounts of caffeine do not improve an inebriated person’s driving skills. The sedative-hypnotic drugs, including barbiturates, are powerful depressants that calm people down or help them sleep. Sleepy or over-sedated drivers, however, are not good drivers. Many over-the-counter drugs produce drowsiness in some people that can affect their driving. Drivers should read the labels and be especially careful with antihistamines, other cold preparations or any medicine that relaxes or promotes sleep. Any drug you take might affect your ability as a driver. If you take more than one drug, or if you mix drugs (especially tranquilizers or other sedative-hypnotics) with alcohol, you could be asking for trouble, on the road and off. If you have doubt about a particular drug or drug mix, check with your doctor or pharmacist. Each year alcohol, a depressant drug that affects coordination, judgement, perception and emotional state, is responsible for half of all American highway deaths. Alcohol increases the depressant effects of tranquilizers and barbiturates. Mixing these drugs, on or off the road, can be extremely hazardous. You lose your judgement when you drink or use drugs. It is often the first thing about you that changes. Loss of judgement, or good sense, affects how you react to sounds, what you see, and the speed of other vehicles around you. Good judgement may be as simply as saying, “No” to a friend who wants to try racing your new car on a county road. However, if you have been drinking or are under the influence of drugs, your good judgement may turn into, “Sure, go ahead, take my new car.” Your ability to reason with your friend has all but disappeared. Do not give in. No one can drink more than one’s limit and drive safely’no matter how much driving experience he or she has had. However, new drivers are affected even more than experienced drivers because they have to think more about what they are doing when they are driving. And, the younger driver is affected more rapidly by alcohol. Even one drink can affect anyone’s driving’young or old. Two drinks in an hour can make anyone an unsafe driver. Courtesy of Texas Department of Public Safety.