Arizona has some of the toughest DUI laws in the country. Driving under the influence (DUI) is also known as driving while intoxicated (DWI). This means that in Arizona a person may be guilty of DUI if found to be operating a motor vehicle while impaired by the influence of alcohol or drugs. Whether a person is “under the influence” depends on a person’s blood alcohol concentration (BAC), which can be determined either through a blood test or a breath test. In the case that drug use is suspected, a urine test will be conducted.