Operating a motor vehicle while under the influence of alcohol or any substance that alters a person's ability to drive safely is illegal everywhere in the United States, including Arizona. Individual states may have different penalties, but a driver is considered legally drunk in every state if the driver's blood alcohol concentration reaches or exceeds 0.08 percent. Beyond this, a law enforcement officer may consider a driver to be incapable of handling a vehicle because of drug or alcohol impairment, and arrest that person even if the BAC level is less than 0.08.
Arizona law states that a driver with a BAC level that is less than 0.05 is not drunk, but this drops to 0.04 for drivers of commercial vehicles. When the BAC level is above 0.05 but below 0.08, other factors, such as a drunk driving accident caused by an impaired driver, can lead to a conviction for drunk driving.
A convicted driver also can be required to serve the community, pay a minimum fine of $250 and be assessed increments of $500 to go into state funds for prison construction, operations and public safety equipment. The last assessment applies in particular to cases where drivers are required by court order to install and then use ignition interlock devices in their motor vehicles for 12 months after their licenses are reinstated.
Penalties increase considerably for repeat violations within seven years after a conviction and can mean a year-long license revocation, sizable fines and additional assessments. These penalties are usually made at the discretion of the judge presiding over a driver's case. A judge may sometimes alter the jail sentence to 1 day instead of 10 days once the driver completes a driver's education program - but without altering any of the other financial or community service penalties. Lastly, a convicted drunk driver can be subject to a civil lawsuit if their illegal conduct leads to an accident that causes injury to another person.
Source: AZDPS.gov, "Overview on Arizona DUI Laws", Accessed Nov. 27, 2014