Impaired driving

Driving under the influence (DUI), or driving while intoxicated (DWI), is the crime of operating a vehicle while impaired by alcohol or other drugs (including recreational drugs and those prescribed by physicians), to a level that renders the driver incapable of operating a motor vehicle safely. People who receive multiple DUI offenses are often people struggling with alcoholism or alcohol dependence.

Traffic accidents are predominantly caused by driving under the influence; for people in Europe between the age of 15 and 29, DUI is one of the main causes of mortality. According to the National Highway Traffic Safety Administration alcohol-related crashes cause approximately $37 billion in damages annually. DUI and alcohol-related crashes produce an estimated $45 billion in damages every year. Between attorney fees, fines, court fees, ignition interlock devices, and DMV fees a DUI charge could cost thousands to tens of thousands of dollars.

With alcohol, a drunk driver's level of intoxication is typically determined by a measurement of blood alcohol content or BAC; but this can also be expressed as a breath test measurement, often referred to as a BrAC. A BAC or BrAC measurement in excess of the specific threshold level, such as 0.08%, defines the criminal offense with no need to prove impairment. In some jurisdictions, there is an aggravated category of the offense at a higher BAC level, such as 0.12%, 0.15% or 0.25%. In many jurisdictions, police officers can conduct field tests of suspects to look for signs of intoxication. The US state of Colorado has a maximum blood content of THC for drivers who have consumed cannabis.

In most countries, sobriety checkpoints, driver's licence suspensions, fines and prison sentences for DUI offenders are used as a deterrent. Anyone who is convicted of driving while under the influence of alcohol or other drugs can be heavily fined or given a prison sentence. In some jurisdictions, impaired drivers who injure or kill another person while driving may face heavier penalties. In addition, many countries have prevention campaigns that use advertising to make people aware of the danger of driving while impaired and the potential fines and criminal charges, discourage impaired driving, and encourage drivers to take taxis or public transport home after using alcohol or drugs. In some jurisdictions, the bar that served an impaired driver may face civil liability. In some countries, non-profit advocacy organizations, a well-known example being Mothers Against Drunk Driving (MADD) run their own publicity campaigns against drunk driving.

...
Wikipedia