Driving under the influence (DUI), driving while impaired/driving while intoxicated (DWI), operating while intoxicated (OWI) is currently the crime or offense of driving or operating a motor vehicle while impaired by alcohol or other drugs (including recreational drugs and those prescribed by physicians), to a level that renders the driver incapable of operating a motor vehicle safely.
With alcohol consumption, a drunk driver’s level of intoxication is typically determined by a measurement of blood alcohol content or BAC; but this can also be expressed as a breath test measurement, often referred to as a BrAC. A BAC or BrAC measurement in excess of the specific threshold level, such as 0.08%, defines the criminal offense with no need to prove impairment. In some jurisdictions, there is an aggravated category of the offense at a higher BAC level, such as 0.12%, 0.15% or 0.25%. In many jurisdictions, police officers can conduct field tests of suspects to look for signs of intoxication. The US state of Colorado has a maximum blood content of THC for drivers who have consumed cannabis.