Michigan’s Legal Limit For DUI

It may come as a surprise to you that Michigan really has no legal limit.  To understand why, it is important to understand a few facts about Michigan’s drunk driving law.

Michigan has always had a two-step law, with OWI, which means Operating While Intoxicated (formerly OUIL/UBAL) being the principal offense and OWVI (impaired driving) be the lesser included. 

The old pre-2003 scheme was for there to be a presumption that if the driver was .10 or above, they were intoxicated.  If above .07 but less than .10, then the driver was presumed to be impaired.  If less than .07 then the driver was presumed to be not impaired or intoxicated.

This changed with .08 in 2003.  The presumptions were removed, and impaired is now any BAC (or no BAC at all) that is not intoxicated.  Of course it is also now literally true that any BAC that is intoxicated is intoxicated, but the legal limit is .08.  So if the prosecutor can prove common law OWI at .05 the driver is guilty of OWI.  If the prosecutor can’t prove OWI at .05 he can still try to prove OWVI.

Here is a summary of the 2003 changes:

OPERATING WHILE INTOXICATED (OWI)

In 2003 Michigan changed the name of the drunk driving from Operating Under the Influence of Liquor (OUIL) to Operating While Intoxicated (OWI). The new OWI offense includes both operating with a blood-alcohol level of .08% or more (UBAL), as well as operating while under the influence of alcohol (UBAL), a controlled substance (OUID), or a combination of alcohol and a controlled substance.

OPERATING WHILE IMPAIRED (OWVI)

Michigan retained the offense of Operating While Visibly Impaired (OWVI) but there is no longer a blood-alcohol threshold used to prove OWI as there was previously.

PRESUMPTIONS WERE REMOVED

As indicated above, under the old law a driver was presumed to be intoxicated OUIL/UBAL) if he or she had a BAC of .10 or greater; and Impaired (OWVI) if he or she had a BAC of greater than .07 but less than .10.  A driver was presumed to not be impaired if he or she had a BAC of .07 or less.

In 2003 those presumptions were removed. Although it is clearly unlawful to drive with a BAC of .08 or more, there is no longer a presumption that a person is intoxicated at that level.  There is also no presumption that the driver is not impaired with a BAC of .07 or less. Thus, it is possible for a prosecutor to charge intoxicated or impaired driving even if a person has a BAC level of .07 or less.