DWI is legal shorthand for driving while intoxicated. This motor vehicle violation is also known as DUI – driving under the influence of drugs or alcohol – and OUI – operating a vehicle under the influence of drugs or alcohol. DWI qualifies as either a misdemeanor or a felony in every state. Proof of DWI includes verification that the individual was driving and evidence that alcohol or drugs were in the driver’s system at the time of a traffic stop.
The most definitive measurement for DWI is blood alcohol content, which pinpoints the percentage of alcohol in the individual’s bloodstream. All states consider someone with a minimum .08 percent BAC to be under the influence of alcohol. Nationally, a commercial driver with a BAC of .04 
percent or more is DWI. Some states have zero tolerance policies for drivers under the age of 21. Typically, law enforcement officers with reason to suspect DWI will seek verification by having the driver breathe into a breath testing device to get a BAC reading, put the person through a field sobriety test or both.
Each state sets its own consequences for DWI. Factors that raise the penalty for a DWI include a high BAC, open alcohol containers in the vehicle, driving with minor passengers and previous DWI convictions. In most cases, convicted drivers must pay fines. Additionally, a person convicted of an initial DWI can lose driving privileges for a period ranging from a minimum of two days in Washington, D.C., to one year in Georgia. Many states mandate ignition interlock devices, especially for repeat offenders, which require drivers to pass breath tests before starting their vehicles. Repeated DWI offenses may result in vehicle impoundment.
Of the 50 states, 37 have enacted alcohol exclusion laws that permit auto insurers to deny medical coverage for an offending driver’s injuries in the event of an alcohol-related crash. Those who drive while intoxicated also risk higher insurance premiums, loss of employment, lifelong disability from injuries, and lawsuits for wrongful death or damages to other parties. To avoid these and other consequences of DWI, an accused driver can seek legal assistance from an attorney.