Section 3.1: Traffic Enforcement & MN DUI/OWI Laws

Section 3.1: Traffic Enforcement & MN DUI/OWI Laws

The Purpose of Traffic Enforcement in Minnesota

Traffic enforcement is a core function of patrol operations under the Minnesota Highway Traffic Regulation Act (Minnesota Statutes Chapter 169). The primary goal is promoting public safety by reducing motor vehicle collisions, injuries, and fatalities. Additionally, traffic stops allow peace officers to detect secondary criminal activity, such as drug trafficking or outstanding warrants. A traffic stop is a seizure under the Fourth Amendment of the U.S. Constitution and Article I, Section 10 of the Minnesota Constitution, requiring a legal justification (typically reasonable articulable suspicion) at its inception.

Driving While Impaired (DWI) - MN Stat. § 169A

Minnesota law uses the term "Driving While Impaired" (DWI) to govern operating a motor vehicle under the influence of alcohol, controlled substances, or other intoxicating substances.

Elements of the Offense and "Physical Control"

Under MN Stat. § 169A.20, it is a crime to drive, operate, or be in physical control of any motor vehicle when under the influence of alcohol, cannabis, or any Schedule I or II controlled substance (excluding cannabis), or when blood alcohol concentration (BAC) is 0.08% or higher.

The concept of physical control is a key element of Minnesota DWI law. A person does not need to be actively driving to be charged. An individual is in physical control if they are in a position to regulate the vehicle's movements or could easily put themselves in a position to drive while impaired. Minnesota courts evaluate the totality of the circumstances to determine physical control, considering:

• Key Location: Whether the keys are in the ignition, on the dashboard, or in the driver's pocket.
• Driver Location: Whether the individual is in the driver's seat, passenger seat, or sleeping in the back.
• Vehicle Condition: Whether the engine is running or warm, and where the vehicle is parked (e.g., on a highway shoulder or in a private driveway).
• Intent/Utility: Whether the vehicle is being used for transportation or merely as temporary shelter.

For example, a person sleeping in the driver's seat with the keys in their pocket while parked on a highway shoulder can be found in physical control, as they could easily wake up and begin driving.

Blood Alcohol Concentration (BAC) Thresholds

Minnesota enforces specific BAC limits based on driver age and vehicle type:

• Standard Limit (0.08%): The per se legal limit for adult drivers (21 and older) operating passenger vehicles.
• Aggravated Limit (0.16%): A BAC of 0.16% or higher is an aggravating factor that increases charge severity and triggers administrative consequences, such as vehicle plate impoundment.
• Commercial Vehicles (0.04%): Minnesota sets a lower BAC threshold of 0.04% for individuals operating commercial motor vehicles.
• School Bus Drivers (0.00%): Under MN Stat. § 169A.31, school bus operators are subject to an absolute zero-tolerance standard. Any detectable alcohol in the body is a crime.
• Underage Drivers ("Not-a-Drop" Law): Under MN Stat. § 169A.33, it is a misdemeanor for any person under 21 to operate a vehicle with any physical evidence of alcohol consumption in their body.

The Implied Consent Law (MN Stat. § 169A.51)

Minnesota's Implied Consent Law dictates that operating a motor vehicle within the state constitutes consent to a chemical test of breath, blood, or urine to determine the presence of alcohol or drugs.

Triggers and the Advisory

An officer can request a chemical test only when they have probable cause to believe the person was operating a vehicle while impaired, and at least one of the following conditions is met:

1. The person has been lawfully placed under arrest for DWI.
2. The person was involved in a collision resulting in property damage, physical injury, or death.
3. The person refused the Preliminary Breath Test (PBT) at the roadside.
4. The PBT indicated a BAC of 0.08% or higher (or 0.04% for commercial drivers).

Before administering an evidentiary test, the officer must read the Minnesota Implied Consent Advisory, which informs the driver that Minnesota law requires the test, refusal is a crime, and they have a limited right to consult with an attorney. Under the state constitution, the driver must be allowed a reasonable time (typically 20 to 30 minutes) to contact an attorney before deciding.

Test Refusal and Warrants

Refusing to submit to a chemical test is a crime (MN Stat. § 169A.20 Subd. 2). For a first-time offender, refusal is a gross misdemeanor (more severe than a standard first-time DWI misdemeanor).

• Breath Tests: Officers may request a breath test without a warrant under implied consent because breath tests are minimally invasive (Birchfield v. North Dakota).
• Blood and Urine Tests: Under State v. Thompson and State v. Trahan, a search warrant is required to compel a blood or urine test. An officer cannot charge a driver with test refusal for blood or urine unless a judicial search warrant has been obtained.

DWI Degrees and Aggravating Factors

DWI offenses are classified into four degrees based on the presence of aggravating factors:

• 4th Degree DWI: Misdemeanor. No aggravating factors.
• 3rd Degree DWI: Gross Misdemeanor. One aggravating factor, or test refusal.
• 2nd Degree DWI: Gross Misdemeanor. Two or more aggravating factors, or one factor plus test refusal.
• 1st Degree DWI: Felony. Three or more prior impaired driving convictions within 10 years, a prior felony DWI conviction, or a prior conviction for felony criminal vehicular operation.

Aggravating Factors include:

• A prior impaired driving conviction or license revocation within 10 years.
• A BAC of 0.16% or higher.
• The presence of a child under 16 in the vehicle (if the driver is at least 3 years older).

Preliminary Breath Test (PBT) vs. Evidentiary Testing

• PBT (MN Stat. § 169A.41): Roadside breath test used solely to establish probable cause for arrest or evidentiary testing. PBT results are inadmissible in criminal trials to prove BAC, but are admissible to challenge the validity of the arrest.
• Evidentiary Test: Performed at a police station using an approved instrument (e.g., DataMaster DMT) or a blood/urine sample analyzed by the Bureau of Criminal Apprehension. These results are fully admissible in court to prove BAC.