Alcohol and other drugs change how you see things and how you react, both mentally and physically. By the time you feel the effects, your judgment and coordination are already impaired, and you don't know you've had too much until it's too late.
Know the rule
Mind-altering drugs like alcohol, marijuana, tranquilizers, antidepressants, speed and meth affect your driving. So can many prescription and over-the-counter drugs (cold, hay fever, pain medications, diet pills): they can slow reaction time, cause dizziness or nervousness, and impair concentration and vision.
Handbook p. 64 ↗Know the rule
The same drug and amount affects each person differently, and can affect you more at one time than another. Weight, emotional state, heart and breathing rate, food, sleep and tolerance all play a part.
Handbook p. 64 ↗Know the rule
Even a small amount of alcohol or drugs reduces your ability to judge a driving situation, decide what to do and act quickly.
Handbook p. 64 ↗Know the rule
Mixing drugs is especially dangerous, especially with alcohol: the drugs multiply each other's harmful effects on concentration and coordination and can cause serious health problems, even death.
Handbook p. 64 ↗Know the rule
Alcohol moves quickly to your stomach, into your blood and to all parts of your body. Driving skills, especially judgment, are affected almost immediately.
Handbook p. 64 ↗Know the rule
Alcohol slows reflexes and reaction time, reduces your ability to see clearly and makes you less alert. You'll have trouble judging distances, speeds and other vehicles' movement, and controlling your vehicle.
Handbook p. 64 ↗Share of all highway deaths alcohol is responsible for
Handbook p. 64 ↗Know the rule
More young people are crippled, maimed and killed by drinking and driving, or by drunk drivers, than by any other cause.
Handbook p. 64 ↗Same alcohol, different drinks
A 12-ounce can of beer, a 5-ounce glass of wine and a cocktail with 1.5 ounces of 80-proof spirits all contain the same amount of alcohol. It's not what you drink, it's how much.
Handbook p. 64 ↗Know the rule
Before taking a prescription or over-the-counter drug, check the label for side effects such as drowsiness or nervousness. Diet and pep pills may make you alert briefly, then bring nervousness, dizziness, poor concentration and distorted vision. If unsure, ask a pharmacist or doctor.
Handbook p. 66 ↗Know the rule
Marijuana users make more driving mistakes, have more trouble adjusting to glare and have more traffic arrests. Although cannabis is legal for some medical purposes, it is illegal for anyone to drive with any detectable level of cannabis in their system.
Handbook p. 66 ↗How much more likely drivers on amphetamines are to be in a crash
Handbook p. 66 ↗Know the rule
Drugs other than alcohol can impair your thinking and driving even more than alcohol, and many prescription drugs combined with alcohol or other drugs can be deadly.
Handbook p. 66 ↗Put it into practice
You took a cold medicine that warns of drowsiness, then had one beer at dinner. Don't drive: even small amounts impair judgment, and mixing drugs with alcohol multiplies the effects. Get a ride or wait.