Driving after drinking is deadly. Yet it still continues to happen across the United States. If you drive while impaired, you could get arrested, or worse — be involved in a traffic crash that causes serious injury or death. Every day, about 28 people in the U.S. die in drunk-driving crashes. That's one person every 52 minutes — 10,000 people every year. These deaths were all preventable. Your life and the lives of others on the road are at risk every time a driver gets behind the wheel after drinking.
How alcohol affects driving ability
Alcohol is a substance that reduces the function of the brain, impairing thinking, reasoning and muscle coordination. All these abilities are essential to operating a vehicle safely.
As alcohol levels rise in a person’s system, the negative effects on the central nervous system increase. Alcohol is absorbed directly through the walls of the stomach and small intestine. Then it passes into the bloodstream where it accumulates until it is metabolized by the liver. A person's alcohol level is measured by the weight of the alcohol in a certain volume of blood. This is called Blood Alcohol Concentration, or BAC. At a BAC of .08 grams of alcohol per deciliter (g/dL) of blood, crash risk increases exponentially. Because of this risk, it’s illegal in all 50 states to drive with a BAC of .08 or higher.
However, even a small amount of alcohol can affect driving ability. BAC is measured with a breathalyzer, a device that measures the amount of alcohol in a driver’s breath, or by a blood test.
The Effects of Blood Alcohol Concentration
| BLOOD ALCOHOL CONCENTRATION (BAC) IN G/DL | TYPICAL EFFECTS | PREDICTABLE EFFECTS ON DRIVING |
|---|---|---|
| .02 | Some loss of judgment; relaxation, slight body warmth, altered mood | Decline in visual functions (rapid tracking of a moving target), decline in ability to perform two tasks at the same time (divided attention) |
| .05 | Exaggerated behavior, may have loss of small-muscle control (e.g., focusing your eyes), impaired judgment, usually good feeling, lowered alertness, release of inhibition | Reduced coordination, reduced ability to track moving objects, difficulty steering, reduced response to emergency driving situations |
| .08 | Muscle coordination becomes poor (e.g., balance, speech, vision, reaction time, and hearing), harder to detect danger; judgment, self-control, reasoning, and memory are impaired | Concentration, short-term memory loss, speed control, reduced information processing capability (e.g., signal detection, visual search), impaired perception |
| .10 | Clear deterioration of reaction time and control, slurred speech, poor coordination, and slowed thinking | Reduced ability to maintain lane position and brake appropriately |
| .15 | Far less muscle control than normal, vomiting may occur (unless this level is reached slowly or a person has developed a tolerance for alcohol), major loss of balance | Substantial impairment in vehicle control, attention to driving task, and in necessary visual and auditory information processing |
Consequences
Driving a vehicle while impaired is a dangerous crime. Tough enforcement of drunk-driving laws has been a major factor in reducing drunk-driving deaths since the 1980s. Charges range from misdemeanors to felony offenses, and penalties for impaired driving can include driver’s license revocation, fines, and jail time. It’s also extremely expensive. A first-time offense can cost the driver upwards of $10,000 in fines and legal fees.
Responsible Behavior
BEING A RESPONSIBLE DRIVER IS SIMPLE: IF YOU ARE DRINKING, DO NOT DRIVE.
- Plan your safe ride home before you start the party, choose a non-drinking friend as a designated driver.
- If someone you know has been drinking, do not let that person get behind the wheel. Take their keys and help them arrange a sober ride home.
- If you drink, do not drive for any reason. Call a taxi, a ride-hailing service, or a sober friend.
- If you’re hosting a party where alcohol will be served, make sure all guests leave with a sober driver.
- Always wear your seat belt — it’s your best defense against impaired drivers.
If you see an impaired driver on the road, contact local law enforcement. Your actions could help save someone’s life.