You can't trust yourself or friends to judge whether you're safe to drive after drinking. Impairment starts long before anyone notices outward signs, and only time sobers you up.
Crash risk rises with alcohol concentration
| Alcohol concentration | Crash risk |
|---|---|
| Slightly above .05 | Doubles |
| .10 | Six times as great |
| .15 | 25 times as great |
Know the rule
A 1.5-ounce jigger of 80-proof liquor, five ounces of table wine, and 12 ounces of beer each contain about the same amount of alcohol. Most people arrested for DUI had been drinking beer.
Handbook p. 129 ↗Know the rule
Alcohol passes through your stomach and small intestine into the bloodstream, almost immediately on an empty stomach. After two to four drinks it impairs reaction time, coordination, balance, vision, and distance judgment.
Handbook p. 129 ↗Know the rule
Aspirin, black coffee, deep breathing, a slap in the face, exercise, or eating won't sober you up. Only time will. Alcohol combined with anger causes much reckless, aggressive driving.
Handbook p. 129 ↗Signs of drunken driving officers look for:
- Speeding: drinkers think they can drive safely fast
- Weaving: trouble steering straight, even within a lane
- Slow driving: overly cautious, slower than traffic
- Jerking motion: jerky steering or acceleration from mental lapses
- Quick stops: sudden stops at signs or lights instead of easing up
Know the rule
Idaho's open container law bars drivers and passengers from drinking or possessing an open alcohol container. Carry unsealed alcohol in the trunk, or behind the last upright seat if there's no trunk.
Handbook p. 130 ↗Know the rule
Ask your doctor whether a prescription affects driving; if it does, let someone else drive. Read over-the-counter drug labels and don't drive if they discourage it. Mixing alcohol and drugs increases impairment.
Handbook p. 130 ↗Drugs and their driving effects
| Drug | Effect |
|---|---|
| Marijuana | Slows reaction; impairs judgment of time and distance |
| Methamphetamine or cocaine | Aggressive and reckless behavior |
| Opioids | Drowsiness; impaired memory and thinking |
| Sedatives | Dizziness and drowsiness |
Preventing impaired driving:
- Offer to be a designated driver, and have that driver take all car keys
- Get a ride to and from parties with drugs and alcohol
- Avoid parties where alcohol and drugs are present
- Talk with friends about the risks of drugged driving
Put it into practice
Friends suggest a pot of black coffee before you drive home from a party. Coffee won't lower your alcohol level; only time does. Hand over your keys to the designated driver or get a ride.