Legal Alcohol Limit in All States
All states have adopted .08 percent as the legal alcohol limit.
If a police officer pulls you over and a test shows that your alcohol content in your breath, blood, or urine is 0.08 percent or over this legal alcohol limit, you have violated the law.
Driving with a Blood Alcohol Concentration (BAC) of .08 percent is unlawful per se.
Per se means that the act is inherently illegal or illegal by itself. No additional proof of impaired driving is necessary. You are considered to have been driving under the influence, regardless of any surrounding circumstances.
In 2018, Utah will, as the first state, lower the legal alcohol limit to .05 percent.
Some states have introduced a second, lower limit, for a lesser charge of driving under the influence.
In New York State, as an example, you will be charged with Driving While Intoxicated (DWI) if a test shows .08 BAC or higher. If your BAC is more than .05 BAC but less than .08, you may be charged with Driving While Ability Impaired by Alcohol (DWAI/Alcohol). There is also a higher limit (.18 BAC) for Aggravated Driving While Intoxicated (Aggravated DWI).
All states and District of Columbia also have zero tolerance laws. The zero tolerance laws apply to anyone under 21 years driving under the influence of alcohol. In most states, the law kicks in, if any alcohol is found in the blood. Some states have specified a limit of .01 or .02 percent.
Can You Drive Legally if You are Below the Legal Limit?
Most people tend to forget that it takes much less than .08 percent to affect driving performance. Some studies show alcohol affects your driving after only one drink.
Under the influence of alcohol, many drivers are more impulsive and adventurous. Alcohol quickly affects judgment, vigilance, recognition, and reaction. When your judgment is affected, you take more risks.
Weaving between lanes, straddle lane lines, driving too slowly, braking erratically, or stopping suddenly and for no apparent reason are some signs of impaired driving.
A police officer can pull you over when he or she has reason to believe that you are driving under the influence. With a Standardized Field Sobriety Test the officer will determine impairment and probable cause of arrest.
The sobriety tests are admissible as evidence in court in most states.
Officers trained to conduct sobriety test correctly identify alcohol-impaired drivers over 90% of the time.
A sworn statement from an officer can be enough to convict you of impaired driving, even if your BAC is below the legal limit, and even without any BAC test at all.
Drugs and the Combination of Drugs and Alcohol
Driving under the influence doesn’t just mean driving under the influence of alcohol. By law, it is also illegal to drive a vehicle under the combined influence of alcohol and any drug or drugs to a degree that renders a person incapable of driving safely.
But laws involving drugged driving vary across the states.
15 states DUI laws make it illegal to operate a motor vehicle with any detectable amount of certain drugs in the bloodstream, regardless of other circumstances (per se statutes). Some states have certain limits for the presence of these intoxicating drugs, others have a zero-tolerance policy.
It is not only illegal drugs that can affect your driving and result in DUI charges. There are countless substances that affect your ability to drive. They include prescription medications as well as over-the-counter drugs. Any drug or combination of drugs and alcohol that impair judgment, alertness, reaction or motor skills are just as unsafe as driving under the influence of alcohol.
Mixing drugs with alcohol often multiply the effects and make you an unsafe driver, even when you are not aware of it.
If an officer and/or drug recognition expert gathers enough evidence of impaired driving, it will often result in a DUI charge. A valid prescription from your doctor is not a defense.
This is also true about Marijuana.
States that allow medical use of marijuana with a valid doctor’s recommendation, still consider it illegal to drive under the influence of this drug if it affects your ability to drive safely.
Use of marijuana and prescription drugs among drivers on America’s roads is more common today, which raises a new safety challenge for lawmakers.