Alcohol, Drugs & Impaired Driving
Alcohol, drugs, and even fatigue or distraction slow your reactions and cloud your judgment behind the wheel. Understanding the laws and the real effects of impairment helps you make the only safe choice: never drive impaired.
BAC Limits and Zero Tolerance
For drivers 21 and older, the nationally standard legal limit is 0.08% blood alcohol concentration, and at or above that level you can be arrested for driving under the influence. Impairment actually begins with the first drink, and you can still be charged at lower levels if your driving is affected. Because drivers under 21 cannot legally drink, zero-tolerance laws set a very low limit, often 0.01% or 0.02%. Exact limits vary by state; for example, one state uses a stricter 0.05% adult limit.
Implied Consent
By choosing to drive on public roads, you give implied consent to submit to breath, blood, or urine testing if you are lawfully arrested for impaired driving. Refusing the test usually triggers an automatic license suspension that is often longer than the penalty for failing the test. This law exists to help enforce impaired-driving statutes and remove dangerous drivers from the road. The penalties for a DUI conviction can include fines, license loss, and jail.
Effects of Impairment and Distraction
Alcohol and many drugs, including some prescription and over-the-counter medicines, slow reaction time, blur vision, and reduce coordination and judgment. Only time can lower your blood alcohol level; coffee, cold showers, and fresh air do not speed the process. Drowsy driving is similar to drunk driving because fatigue delays your reactions, so pull over and rest if you feel sleepy. Distractions such as texting, phone calls, and eating take your eyes and mind off the road and greatly raise crash risk.