Chapter 4: DUI / DWI Laws

Operating a vehicle while intoxicated (OWI) is one of the most dangerous actions a driver can take, leading to thousands of preventable deaths and injuries each year. Indiana enforces strict laws against impaired driving to protect all road users from these severe risks. Understanding these laws, including Blood Alcohol Concentration (BAC) limits, the principle of Implied Consent, and the significant criminal and administrative penalties, is crucial for passing the knowledge exam and for making responsible choices that save lives.

DUI & Implied Consent

In Indiana, it is illegal to operate a vehicle while intoxicated. The legal term is Operating While Intoxicated (OWI), though it is commonly known as Driving Under the Influence (DUI) or Driving While Intoxicated (DWI). Intoxication is not limited to alcohol; it includes being impaired by illegal drugs, prescription medication, over-the-counter drugs, or any substance that affects a person’s ability to drive safely. A driver can be convicted of OWI even if their BAC is below the legal limit if there is sufficient evidence that they were impaired.

Blood Alcohol Concentration (BAC) Limits

A driver’s BAC is the percentage of alcohol in their bloodstream. Indiana law establishes “per se” BAC limits, meaning that operating a vehicle with a BAC at or above these levels is automatically illegal, regardless of whether the driver appears impaired.

• Drivers 21 and Older: It is illegal to drive with a BAC of 0.08% or higher.
• Drivers Under 21: Indiana has a “Zero Tolerance” law. It is illegal for a person under 21 to drive with a BAC of 0.02% or higher. This low threshold means that even one drink can result in an OWI charge.
• Commercial Drivers: For drivers operating a commercial vehicle (requiring a CDL), the legal BAC limit is 0.04% or higher.

The “Implied Consent” Law

Under Indiana’s Implied Consent law (IC 9-30-6), any person who operates a vehicle has automatically given their consent to submit to a chemical test (breath, blood, or urine) if a law enforcement officer has probable cause to believe they are intoxicated. This is a condition of holding driving privileges in the state.