When is a driver presumed to be impaired in Arizona?

In Arizona, a driver is presumed to be impaired when their blood alcohol concentration (BAC) reaches 0.08%. This level is established by law as the threshold for driving under the influence (DUI) for most adult operators of motor vehicles. When an individual's BAC is at or above this limit, they are presumed to be impaired regardless of whether any other proof of impairment is present.

This presumption plays a critical role in law enforcement and legal proceedings, as it provides a clear standard for detecting and prosecuting DUI offenses. Thus, any BAC measurement at or above 0.08% serves as sufficient evidence for a conviction of DUI, reflecting a recognition of the increased risk of accidents and impaired judgment associated with higher alcohol levels in the bloodstream.

Other BAC levels mentioned, such as 0.07%, 0.09%, and 0.10%, do not constitute the legal presumptive threshold in Arizona. Instead, while a BAC of 0.07% might indicate impairment, it does not reach the level where the driver is automatically presumed to be impaired under state law. A BAC of 0.09% or 0.10% would still be handled as a DUI but do not serve as the specific legal threshold for presumed