Drunk driving law is the branch of law for the offense of operating a motor vehicle while intoxicated by drugs or alcohol.
Criminal DWI statutes provide that it is a crime to drive a vehicle if he has a certain percentage of alcohol in his blood. The percentage varies from state to state. For example, the California DWI statute provides for a 0.08 percent blood alcohol level.
State DWI laws also create a presumption that the blood alcohol percentage is satisfied if a chemical test conducted within a certain number of hours after driving shows the driver has the required percentage alcohol in his blood at the time of the test.
Criminal DWI statutes usually authorize the police to obtain blood samples to determine the alcohol content of a driver's blood. Police may also request drivers take a breathalyzer test or submit to urinalysis screening.
Conviction of a DWI offense usually results in a heafty fine, suspension of the operator's driver's license, and probation or jail time. Subsequent offenses often result in incarceration in prison. Drivers may be charged with more serious offenses when they injure others while they are operating a car while under the influence of drugs or alcohol.