A “Driving While Ability Impaired by Alcohol” (DWAI) charge is what is called a “lesser included” charge of DUI. That means that although someone’s level of impairment may not reach the level of DUI, they may still be guilty of DWAI.
Specifically, DWAI means:
“. . . driving a motor vehicle or vehicle when a person has consumed alcohol or one or more drugs, or a combination of both alcohol and one or more drugs, that affects the person to the slightest degree so that the person is less able than the person ordinarily would have been, either mentally or physically, or both mentally and physically, to exercise clear judgment, sufficient physical control, or due care in the safe operation of a vehicle.”
Very simply, someone is guilty of DWAI when some substance (or substances) makes them less able than normal to safely operate a motor vehicle. For example, if your normal ability to operate a motor vehicle can be scored as a 10, and after a drink, you are now able to operate a motor vehicle at only a 9.9, technically you are guilty of DWAI.
However, unlike DUI, there is no per se limit for blood alcohol content over which you are automatically guilty. But there is a presumption in Colorado that you are impaired if your blood alcohol content is over 0.05 but less than 0.08. See C.R.S. 42-4-1301(6)(a)(II). Regardless, a BAC anywhere below 0.08 can be a helpful fact for negotiation, and in some instances may be possible to plead your case to a non-alcohol charge.