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Driving under the influence

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Driving under the influence of alcohol, drunk driving, drinking and driving (American or Canadian English), or drink-driving (Australian, Irish, British or New Zealand English), is the act of operating a motor vehicle (and sometimes a bicycle or similar human-powered vehicle) after having consumed alcohol (ethanol) or other drugs, to the degree that mental and motor skills are impaired.


In addition to driving under the influence of alcohol and driving under the influence of other drugs, a third "DUI" offense consists of driving under the combined influence of alcohol and other drugs. The drugs causing or contributing to the impairment need not be illegal, but can consist of lawfully prescribed or over-the-counter medication. Anti-drunk-driving advertising campaigns have aimed to raise awareness of the legal situation and the dangers of driving while intoxicated. Drunk-driving is responsible for a large number of deaths, injuries, damage and accidents every year. In most international jurisdictions, anyone who is convicted of injuring or killing someone while under the influence of alcohol or drugs can be heavily fined, as in France,[1] in addition to being given a lengthy prison sentence.

The specific criminal offense may be called, depending on the jurisdiction, driving while intoxicated (DWI), driving while impaired (also DWI), operating while intoxicated (OWI), operating a motor vehicle while intoxicated (OMVI), driving under the influence [of alcohol or other drugs] (DUI), driving under the combined influence of alcohol and/or other drugs, driving under the influence per se or drunk in charge [of a vehicle]. Such laws may also apply to boating (as in Canada[2]), piloting aircraft, and even bicycling in some states such as California.

Historically, guilt was established by observed driving symptoms, such as weaving; administering field sobriety tests, such as a walking a straight line heel-to-toe or standing on one leg for 30 seconds; and the arresting officer's subjective opinion of impairment. Starting with the introduction in Norway in 1936 of the world’s first per se law which made it an offense to drive with more than a specified amount of alcohol in the body, objective chemical tests have gradually supplemented the earlier purely judgmental ones.

Today's statutes commonly provide for two separate and distinct criminal offenses. The first is the traditional "drunk driving" offense, consisting of driving under the influence of alcohol and/or drugs. Evidence to support this crime generally comes from the officer's observations (erratic driving, slurred speech, unsteady gait, etc.), performance on field sobriety tests, and a legal (and generally rebuttable) presumption of intoxication from a blood alcohol test result over the legal limit. The second offense is the more recent so-called "per se" offense: rather than focusing on impairment the crime consists entirely of having a given blood alcohol content (BAC) at the time of driving, regardless of the individual's tolerance to alcohol. Both offenses may be charged, and the defendant may be convicted of both; if a blood alcohol test result was not obtained, only the traditional "DUI" offense will be charged.

BAC is most conveniently measured as a simple percent of alcohol in the blood by weight. It does not depend on any units of measurement. In Europe it is usually expressed as milligrams of alcohol per 100 millilitres of blood. However, 100 milliliters of blood weighs essentially the same as 100 milliliters of water, which weighs precisely 100 grams. Thus, for all practical purposes, this is the same as the simple dimensionless BAC measured as a percent. Since 2002 it has been illegal in all 50 US states to drive with a BAC that is 0.08% or higher.

Driving while consuming alcohol is generally illegal, though driving after drinking remains legal. In some jurisdictions it is also illegal for an open container of an alcoholic beverage to be in the passenger compartment of a motor vehicle or in some specific area of that compartment.

United States

Main article: Drunk driving (United States)

All 50 states now have two statutory offenses[1]. The first is the traditional offense, variously called driving under the influence of alcohol (DUI), driving while intoxicated/impaired (DWI) or operating while intoxicated/impaired (OWI). The second and more recent is the so-called illegal per se offense of driving with a blood-alcohol concentration (BAC) of 0.08% (previously 0.10%) or higher. The first offense requires proof of intoxication, although evidence of BAC is admissible as rebuttably presumptive evidence of that intoxication; the second requires only proof of BAC at the time of being in physical control of a motor vehicle. An accused may be convicted of both offenses, but may only be punished for one.

It is also a criminal offense in all states to drive a vehicle while under the influence of drugs DUID, or under the combined influence of alcohol and drugs; the drugs themselves need not be illegal, but can be prescription or even over-the-counter. This offense requires evidence of impairment as a result of the drugs or drugs and alcohol, although some states have passed laws making driving with the mere presence of certain drugs a criminal offense.

Some states also include a lesser charge of driving with a BAC of 0.05%; other states limit this offense to drivers under the age of 21. All states also now have zero tolerance laws: the license of anyone under 21 driving with a BAC of .01% or higher (.02% in some states) will be suspended.

The blood-alcohol limit for commercial drivers 0.04%. [3]

Pilots of aircraft may not fly less than eight hours after consuming alcohol, while under the impairing influence of alcohol or any other drug, or while showing a blood alcohol concentration equal to or greater than 0.04 grams per decilitre of blood.[2]

The various versions of "driving under the influence" generally constitute a misdemeanor (punishable by up to one year in jail) . However, the offense may be elevated to a felony (punishable by a longer term in state prison) if the incident caused serious injury (felony DUI), death (vehicular manslaughter or vehicular homicide), or extensive property damage (a state specified dollar amount) or if the defendant has a designated number of prior DUI convictions within a given time period (commonly, 3 prior convictions within 7 years). California, which is being followed by a growing number of states, now charges second-degree murder where the legal state of mind of malice exists -- that is, where the defendant exhibited a reckless indifference to the lives of others [4].

A severe punishment for drunk driving is already under way in the state of Ohio for DUI offenders convicted of aggravated vehicular homicide to qualify for capital punishment. The new laws are a result of groups of friends and family of drunk driving victims engaging in active campaigns to get the same justice as victims of other forms of murder. The logic of these laws is that drunk driving is premeditated, and because aggravated vehicular homicide is a felony in both states, the act of killing someone in the commission of such a crime qualifies for a charge of felony murder in the first degree.[How to reference and link to summary or text]

Administrative License Suspension (ALS) · If you are stopped for drunk driving and you refuse to take the sobriety test, or if your test results exceed the legal limit of Blood Alcohol Concentration (BAC), the officer can take your driver's license on the spot, and the suspension begins immediately.[How to reference and link to summary or text] · Depending on previous offenses or refusals, you can have your license automatically suspended for a period of 90 days to five years.

An SR-22 is an official documentation required to redeem a suspended drivers license and get your car registered at the local department of Vehicles (DMV). A SR22 Filing is a form issued by an insurance company which removes a suspension order placed by the DMV's office on your driving privilege. The most common reason for an SR22 filing is when you are arrested for Driving Under Intoxication (DUI) or Driving While Intoxicated (DWI). The filing provides a guarantee to the state that an insurance company has issued at least minimum liability coverage for the person making that filing and that the insurance company will notify the DMV should the insurance ever lapse for any reason.

Penalties for driving under the influence commonly include incarceration, fines, driver's license suspension or revocation, mandatory attendance at DUI schools, community service, probation and, increasingly, installation of a Ignition interlock device. In some jurisdictions, the defendants may also forfeit their vehicles if they're convicted and sentenced.


Driving under the influence of alcohol is a generic term for a series of offences under the Canadian Criminal Code. The main offences are operating a motor vehicle while the ability to do so is impaired by alcohol or a drug, contrary to section 253(a) of the Canadian Criminal Code, and operating a motor vehicle while having a blood alcohol concentration of greater than 80 milligrams of alcohol in 100 millilitres of blood, contrary to section 253(b) of the Criminal Code. See Criminal Code Sections 253 to 259 Both offences can be committed by a person who is actually operating or driving a motor vehicle, vessel, aircraft, or railway equipment or by a person who has care or control of such a vehicle. Care or control includes actual care or control and presumed care or control section 258(1)(a) where the person occupies the driver's seat. The latter is often the case where police find an individual sleeping behind the wheel.

The offences are usually investigated by the police coming across a driver with either an erratic driving pattern or who has been pulled over. The police may immediately have grounds to arrest for impaired driving and make an approved instrument demand section 254(3). Those grounds are based on various indicia of impairment. If the police merely have a suspicion of alcohol in the individual's body, they may make a demand section 254(2)that the driver give a sample of his breath into an approved screening device, which will determine the driver's blood-alcohol concentration on a preliminary, non-evidentiary basis. Based on the screening device results, if the police believe on reasonable and probable grounds that the driver is committing an offence under section 253 of the Criminal Code, the police can demand that the driver go to the police station to give samples of his breath for an approved instrument test, which would be used to prosecute the driver for over 80 milligrams of alcohol in 100 millilitres of blood.

The minimum punishments for impaired driving or driving over 0.08% are:

  • For the first offence: $600 fine, 1-year driving prohibition; or jail time
  • For the second offence: 14 days jail, 2-year driving prohibition
  • For the third or subsequent offence: 90 days jail, 3-year driving prohibition.

In addition to the federal criminal laws, all provincial governments have enacted their own measures against impaired driving. Such laws complement the federal laws (part of the double aspect doctrine of Canadian constitutional law). Some provinces will suspend a driver's licence upon him or her being charged with impaired driving, rather than being convicted. Some provinces will automatically impose a licence suspension that runs longer than the driving prohibition handed down by the court. Provinical and federal driving prohibitions run concurrently if imposed for the same offence(s).

In Ontario, a person convicted of a DUI must also complete an 8 month training course and install an ignition interlock device for a period of one year after the licence suspension. [5]

Jail time can be imposed for high-range readings above 0.15%, even for first offences.

Foreigners with recent (in the past 5 years) drunk-driving criminal convictions are generally refused entry at the border.

On January 27, 2001, Andrey Knyazev, a Russian diplomat in Canada killed a Canadian woman while drinking and driving. He was imprisoned in Russia. This incident triggered a crackdown on drunk driving by diplomats in Canada.

On Dec 15, 2005, Charly Hart of Watford, Ontario, a man with a 35-year history of impaired driving which included thirty-nine convictions, was on the occasion of his latest such conviction sentenced to six years in prison, the most severe penalty ever handed down in Canada when the offence did not involve a fatality, and the maximum sentence permitted under the law.[6]


Driver drug testing

A road sign in Victoria, Australia warning drivers about drug testing.

Road laws are state or territory based, but all states and territories have set the maximum BAC at 0.05%.

  • Australian Capital Territory
    • 0.02% for drivers holding a learner, provisional, probationary or restricted licence; or for drivers of a heavy vehicle (>4,500 kg GVM), dangerous goods vehicle, Commonwealth (government) vehicle, public passenger vehicle (e.g. taxi or bus), private hire car or restricted hire car
    • 0.05% for motorcyclists and all other drivers
  • New South Wales
    • Zero for Learner and Provisional licences
    • 0.02% for Drivers of vehicles of "gross vehicle mass" greater than 13.9 tonnes, vehicles carrying dangerous goods or public vehicles such as a taxi or bus.
    • 0.05% for all other drivers
  • Northern Territory
    • Zero for provisional (probationary) licence holders.
    • 0.05% for all other drivers.
  • Queensland
    • A Zero limit applies to the drivers of trucks, buses, articulated vehicles, vehicles carrying dangerous goods, pilot vehicles, taxis, all learner drivers and provisional drivers under 25 years of age.
    • 0.05% for other drivers.
  • South Australia
    • Zero limit for learner, provisional, probationary, heavy (greater than 15 tonne) vehicle, taxis, licensed chauffeured vehicles, dangerous goods, and bus licences.
    • 0.05% for all other drivers.
    • Zero limit for methamphetamine, Cannabis and MDMA.
  • Tasmania
    • Zero limit for learner, provisional, truck, bus, and taxi licences.
    • 0.05% for all other drivers.
  • Victoria
    • Zero limit applies for unlicensed drivers, holders of learner permits and probationary licences, "professional" drivers, and certain relicensed drink-drivers.
    • Below 0.05% for most other drivers.
    • Zero limit for methamphetamine, Cannabis and MDMA.
  • Western Australia
    • 0.02% for learner and provisional (probationary) licence holders.
    • 0.05% for all other drivers.

In Australia, laws allow police officers to stop any driver and perform a random breath test without reason. Roadblocks can be set up - for example leading out of town centres on Friday and Saturday nights, or during football or other events - where every single driver will be breath-tested. This differs from UK and US laws where police generally have to have a reason to suspect drinking, before issuing a breath test.

There are also other restrictions for Victorian drivers:

    • Limits apply within 3 hours of driving - that is, Police can require a person to submit to an alcohol or drugs test within 3 hours of driving and it is an offence to fail that test (see Road Safety Act 1986, ss. 49, 53 and 55E).
    • Licences cancelled for certain serious drink-driving offences may only be reissued after obtaining a court order. This is the case for repeat offenders, and first offenders above 0.15% . In such cases, the relicensed driver is subject to a zero limit for 3 years following relicensing, or for as long as the person is required to use an alcohol interlock.
    • Alcohol interlocks must be imposed whenever a repeat drink-driver is relicensed.
    • A court also has discretion to impose an alcohol interlock when relicensing a first offender in certain serious cases, generally when the offence involves a BAC of 0.15% or higher.
    • If a doctor sees any patient who is aged 15 years or over as a result of a motor vehicle accident, the patient must allow the doctor to take a blood sample for testing for alcohol and drug content in a way that preserves the chain of evidence. If this process is skipped the doctor may not be able to discover the alcohol blood level. The results can be used as evidence in subsequent court proceedings.
    • The law allows a police officer to require any driver (or any person who has driven a vehicle within the last three hours) to perform a random saliva test for methamphetamine, Cannabis or MDMA, all of which are subject to a zero limit (see Road Safety Act 1986: ss. 49, 55E & 55D)


Note: "Zero" usually means "below detection limit".

Turkey’s 0.05% limit only applies to passenger-less compact vehicles; for all others it’s 0.00%. In Germany the 0.05% limit is effective unless you’re arrested for another traffic offence, in which case it drops to 0.03%




Middle East

  • Egypt : 0.05%
  • Iran: No Limit, drinking alcohol is illegal in Iran.
  • Israel: 0.05%
  • Jordan: Zero
  • Kuwait: No Limit, drinking alcohol is illegal in Kuwait.
  • Saudi Arabia: No Limit, drinking alcohol is illegal in Saudi Arabia.

East Asia

  • China: >20mg/100ml (RMB 200-500 fine, 1-3 months license suspension); >80mg/100ml (up to 15 days prison, 3-6 months license suspension, RMB 500-2000 fine) Ministry of Public Safety
  • Hong Kong: 0.05% If driving under alcohol influence beyond legal limit, one can be fined and jailed up to 3 years.
  • Japan: Zero
  • Republic of Korea: 0.05%

Western Pacific

Central Asia

South Asia

South-East Asia


  1. Alcohol-Related Laws: Full Report by State
  2. 14 CFR 91.17, also known as Federal Air Regulation 91.17
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 3.20 3.21 3.22 3.23 3.24 Blood Alcohol Concentration Limits Worldwide, International Centre For Policy Studies. Page retrieved 30 October 2006
  4. UK Government Advice on Gibraltar Page retrieved 30 October 2006.
  5. El alcohol y la conducción (page in Spanish). Page retrieved 30 October 2006.
  6. This is according to section 185 of Motor Vehicles Act 1988. On first offence, the punishment is imprisonment of 6 months and/or fine of 2000 Indian Rupees (INR). If the second offence is committed within three years, the punishment is 2 years and/or fine of 3000 Indian Rupees (INR). The clause of 30 mg/dL was added by an amendment in 1994. It came into effect beginning 14 November 1994.

See also

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