The Basics of Driving Under the Influence of Drugs

Driving under the influence of drugs other than alcohol can still get you in a lot of trouble with the law if you’re pulled over. Those who drive while under the influence (DUI) or while intoxicated (DWI) are more likely to cause fatal accidents, so all states take them as serious charges. Understanding the differences between drug and alcohol influences can help you understand how your case may play out if you’re charged.

Driving Under the Influence of Alcohol

Police determine if a person is too intoxicated to drive by measuring their blood alcohol concentration (BAC) levels. If BAC is higher than .08%, a person may be given a DUI. It’s important to note that in some states, a distinction is made between being under the influence of alcohol and being fully intoxicated. In these cases, a DUI is less severe than a DWI, and some jurisdictions mandate proof showing the driver’s skill was influenced.

Driving Under the Influence of Drugs

Determining if a person’s driving ability has been affected by drugs is a lot more difficult, mainly because some drugs can stay in the blood well past their given effects have worn off. For example, marijuana can still be detected in the blood a month after use, but that detection doesn’t mean it was impairing the person driving. Sometimes police experts are brought in who can identify signs of impairment caused by drug use, including abnormal eye movement and behavior.

Per Se Laws

Some states have laws that make it illegal to operate a vehicle with any drugs in a person’s system. This includes drugs a doctor has prescribed. Other states say that no person under 21 years of age can drive with any drug in their system, or that drug addicts are not permitted to drive. You may be tested for drug use through a blood or urine sample.


You may be arrested if you are found under the influence of drugs while driving, especially if you are still impaired. Planes, boats and bikes also fall into DUI categories, so it’s always best to avoid drug use if you plan to operate anything that moves. You may receive time in jail up to six months, get fined, or lose your license.

You can always contact an attorney who deals with DUI cases to discuss your situation. Everyone is different, and there may be laws you aren’t aware of that can impact your charges. Do not hesitate to set up a consultation with a criminal justice lawyer, like the ones at May Law, LLP, as soon as possible. The sooner that you begin the process, the more time you will have to build a solid case.