DUI vs DWI: Differences Explained

That’s a great question! There is no one definitive answer because each state’s laws vary. In general terms, DUI stands for Driving Under the Influence while DWI is short for Driving While Impaired. That sounds simple enough, but the terms DUI and DWI are defined by several different factors including the level of intoxication, the age of the offender, and the substance or circumstances causing the impairment.

The best way to gain an understanding of either charge is to consult legal counsel, such as a Springfield DWI attorney.

How Can a Police Officer Tell if Someone is Driving Drunk?

The signs that someone is driving while drunk can be obvious or very subtle and police officers can make traffic stops based on what the drivers do. Obvious signs include erratic lane switching, swerving, speeding, sudden braking or stopping, and colliding into other vehicles, objects, or buildings. More subtle indicators include driving across the center or yellow line. If an officer can document that the car crossed the centerline just twice, the officer can stop the car and check for driver impairment.

How is Impairment Detected?

We’ve all seen situations in TV shows and movies when someone is being given Field Sobriety Tests, usually with a humorous twist, but these tests are no joke. There are things that the human brain can’t process while intoxicated, such as doing two things at once. That’s why tests such as closing your eyes and touching your nose at the same time can measure impairment. The brain will choose one task to focus on while the other is ignored or done poorly. The simple act of standing still while reciting the alphabet is difficult for someone who is impaired by alcohol or drugs.

DUI

Driving Under the Influence usually refers to alcohol intoxication. The allowable levels of BAC, or blood alcohol concentration, also vary from state to state and can start at as low as 0.05 percent. If the driver has a BAC that is higher than the allowable limit for that state, the driver is charged with DUI.

DWI

Driving While Impaired can mean that the driver is intoxicated or has been using drugs or other illegal substances that cause lapses in judgment. In some states, lack of sleep is considered enough of an impairment to warrant an arrest or citation. Other drugs can include marijuana, methamphetamine, cocaine, pain killers, inhalants, and medications. Whether the substance was illegally obtained or prescribed by a doctor, the laws still prohibit people from driving after their use. DWI laws can also be used for minors depending on their level of impairment.

A Few Twists

There is one thing that is not implicitly stated in the law but is everyone’s responsibility to know. It’s legal to possess and use controlled substances, like opioids, that have been prescribed by a physician. It’s even legal to own, grow, sell, and use marijuana in states that have legalised those activities and usage, but it is not okay to use those substances and then drive. Driving after using them is still illegal.

There is also one more element to DUI and DWI offenses. It’s called “being in actual physical control of a vehicle” while intoxicated or impaired. That means that the driver may be passed out or unable to turn the key and work the car’s pedals, but the fact that the offender is in the driver’s seat, possesses the keys to the car, and could turn on the car and operate it, is enough to warrant a charge of DUI or DWI.

How is Blood Alcohol Content Measured?

Sometimes a breathalzer can be used during Field Sobriety Tests to determine impairment before an arrest is made, but with or without that, most drunk drivers who are physically capable are required to take an Intoxilyzer Test. For states that carry “Implied Consent” laws, drivers agreed to take the test when they received their licenses, so refusing the test results in another criminal charge. When the driver blows into the machine, it measures the alcohol content. The results of this test are used to determine how the driver is charged.

When the impairment has been caused by drugs or medications, blood and urine tests are better indicators. Urine and blood tests can also be used to determine the blood alcohol content, but they are not as reliable as Intoxilyzer tests and are not preferred methods.

After the Arrest

The offender will need to proceed by seeking legal counsel. These attorneys can explain the laws of the state where the arrest took place and why the DUI or DWI charge was appropriate for the circumstances.

Whether the charge is DUI or DWI, they are serious offenses and carry substantial penalties.