Though the details vary from state to state, being charged with a DUI or a DWI generally means a law enforcement officer determined you were intoxicated and unable to drive safely. DUI and DWI may sound identical, but some states classify them as separate crimes.
The term DUI stands for “driving under the influence” and DWI stands for “driving while impaired” or “driving while intoxicated.” Both terms refer to driving while being impaired by drugs or alcohol. Depending on where you live, you may also see terms with other acronyms:
- OWI: operating while intoxicated
- OUI: operating under the influence
- DWAI: driving while ability impaired
- DUAC: driving with unlawful alcohol concentration
These may be the same as DUI or DWI charges, though some states treat them differently.
Because each state has its own term for impaired driving, it’s a little difficult to draw a clear distinction between DUI vs. DWI. We recommend researching your local laws to find out if the terms are different and what factors contribute to each.
How Are DUIs And DWIs Measured?
If you’re pulled over and suspected of driving under the influence, you may be subjected to a field sobriety test. Police officers use these tests–which assess reaction time, motor skills, and ability to focus one’s eyes–to establish probable cause for arresting someone on DUI or DWI. Officers can estimate a person’s blood alcohol content or blood alcohol concentration (BAC) based on how they perform during the test.
The federal legal BAC limit is 0.08 percent, which most states set as their benchmark for drunken driving. Utah has a lower legal limit: 0.05 percent. Most states set a lower legal limit for underage drivers and those who operate commercial vehicles. In those cases, penalties are also much higher.
If you fail a field sobriety test, you may be subject to a Breathalyzer test, which measures your BAC.
What Are Zero-Tolerance DUI Laws?
Though the federal government set the legal BAC limit at 0.08 percent, every state has a lower legal BAC level for underage drivers. Every state has a zero-tolerance law for underage drinking and driving, so if you’re under the age of 21, it’s a criminal offense to drive with any amount of alcohol in your bloodstream.
The table below compares the federal BAC limit with each state’s zero-tolerance limit.