When it comes to drinking and driving, most people are aware of the legal blood alcohol concentration (BAC) limit of .08% in Iowa.
However, many may not fully understand the concept of “per se” intoxication and how it can lead to arrests for operating while under the influence (OWI) even when their BAC doesn’t exceed .08%.
Why does “per se” intoxication matter?
“Per se” intoxication is a term used to describe a situation where an individual is considered legally intoxicated regardless of whether they show any visible signs of impairment. In other words, if you blow .08% or higher on a breath test, the police don’t need any further probable cause to make an arrest. You could appear sober, but be legally drunk.
“Per se” laws offer an objective standard for law enforcement officers to assess impairment. This is important because subjective assessments of impairment can vary from one officer to another, making it challenging to enforce drunk driving laws consistently.
Blowing over a .08% isn’t the only consideration in play
You can still be charged with an OWI, however, even with a BAC reading of below .08%. Officers typically look for additional evidence of impairment through:
- Field sobriety tests: Officers may administer various field sobriety tests to assess your level of physical and cognitive impairment. These tests are notoriously subjective, but that won’t stop an officer from using them to judge you.
- Personal observations: Officers may look for stereotypical signs of intoxication, including slurred speech, bloodshot eyes and erratic driving. Even the way you respond to the officer (if it’s belligerent or irrational) can be used to measure sobriety.
OWI laws also apply to driving under the influence of drugs, including prescription medications and illicit substances.
While a BAC of 0.08% is a common threshold for arrest, it’s essential to recognize that DUI arrests are not solely based on this measurement. To stay safe and avoid legal trouble, it’s best to plan ahead and designate a sober driver or use alternative transportation if you’ve been drinking. If you do make a mistake, find out more about your defense options by seeking legal guidance as soon as you possibly can.