Drink driving

sober2strapKey facts

  • In 2017, 250 people in Great Britain were killed in crashes where at least one driver was over the drink-drive limit [1];
  • Fatalities involving at least one driver over the alcohol limit accounted for 13% of road deaths in 2018 [2];
  • Two-thirds of drink-drive fatalities in 2017 were men, and a quarter of all people who died in drink-drive crashes in 2017 were aged 16-24 [3]; 
  • For every four deaths in collisions involving a drink-drive offence between 2010 and 2013, one more death happened in a collision at a lower blood alcohol level [4];
  • It is estimated that lowering the drink-drive limit in 2010 could have saved 25 lives and prevented 95 serious injuries between 2010 and 2013 [5].


Drink driving is one of the biggest killers on our roads. It is estimated that 13% of all road deaths in Britain in 2018 resulted from crashes where at least one driver was over the alcohol limit [6]. A further 25 road deaths per year are thought to be caused by drivers who are under the drink-drive limit, but who have significant amounts of alcohol in their blood [7].

In 2017, 250 people were killed by drivers under the influence of alcohol. This was more than in any year since 2009, and 20 more than in 2016 [8].

Even the smallest amount of alcohol affects safe driving. These deaths, and the many more serious injuries, can only be stopped if all drivers pledge to not drink any alcohol – not a drop – before they get behind the wheel. Improving government policies can help encourage drivers to be safe – evidence from around the world shows that taking steps such as lowering drink drive limits and stepping up police enforcement checks are highly effective in cutting drink-drive casualties.

Learn more: Use Brake's interactive resource to bust the myths on drink driving.

Who drink-drives?

The most recent RAC Report on Motoring found one in five (19%) drivers admit to driving while over the drink-drive limit. According to a survey of 1,000 drivers by Brake and Direct Line, a similar proportion (20%) admit driving the morning after having a lot to drink, when they are likely to still be over the limit [9].

Certain types of driver are more likely to be in drink-drive crashes:

  • Two-thirds (66%) of people killed in drink-drive crashes in 2017 were men [10];
  • Four-fifths (79%) of drivers who fail breath tests following crashes are men [11], and almost twice as many men as women admit to drink-driving [12];
  • Young driversaged under 20 have the highest level of drink-drive crashes per distance travelled (97 crashes per billion miles) [13];
  • A quarter (25%) of all people who died in drink-drive collisions in 2017 were aged 16-24 [14].

How much is too much?

In England and Wales, it’s legal to drive with a blood-alcohol concentration (BAC) of 80 milligrams of alcohol per 100 millilitres of blood (80mg/100ml). This is the highest limit in Europe.

In most of Europe, including Scotland, the blood alcohol limit is 50mg/100ml, and in many countries it is even lower. For example, in Sweden, the legal limit is 20mg/100ml for all drivers – effectively zero tolerance – while Hungary, Romania, Slovakia and the Czech Republic do not allow drivers to drink any alcohol at all [15].

There is no failsafe way to tell how much alcohol will put you over the limit, or to convert the BAC limit into how many units you can have: the concentration of alcohol in blood depends on various factors. These include your weight, age, gender, or how much you have eaten before drinking.

Even very small amounts of alcohol affect your driving. Drivers with 20-50mg alcohol per 100ml of blood are at least three times more likely to die in a crash than those with no alcohol in their blood [16]. Drivers with BAC of 10mg/100ml, far below the UK or European drink drive limits, are 46% more likely to be at fault in collisions than sober drivers [17], and when they crash, do more damage than sober drivers [18]. That’s why the only safe amount to drink if you’re driving is nothing at all – not a drop.

Take action: Support Brake’s Driving for Zero campaign for zero tolerance on drink driving.

What are the penalties for drink driving?

In the UK if a driver is found to be over the drink-drive limit, and/or driving while impaired by alcohol, they can receive a maximum penalty of six months in prison, an unlimited fine and an automatic driving ban of at least one year. If a driver kills someone while under the influence of alcohol, they can be charged with causing death by careless driving while under the influence of drink or drugs (Section 3A of the Road Traffic Act 1988 (as amended by the Road Traffic Act 1991, section 3)), which carries a maximum penalty of 14 years in prison and an unlimited fine.

How do the police catch drink drivers?

In the UK, police can stop and breathalyse you if they have reason to suspect you have been drinking – for example, if you are driving erratically. They can also breathalyse you if you have committed another traffic offence (such as speeding or driving without a seat belt) or if you are involved in a crash [19].

In many countries police have the power to stop and breathalyse drivers at random, with no need to suspect the driver is under the influence. For example, police may randomly test drivers near pubs and clubs late at night. Random testing is allowed in most EU countries [20]. Random breath-testing has been found to be highly effective in reducing drink-drive casualties without over-burdening the police and criminal justice system [21].

In some countries, including more than half of EU member states, police can also set up sobriety checkpoints. Police will test either a random selection, or all drivers passing the checkpoint [22].

What does alcohol do to the body?

Alcohol is a depressant and even small amounts (such as half a pint of lager) affect your reaction times, judgement and co-ordination. It also makes you drowsy and affects your vision and how you judge speed and distance [23].

Alcohol also makes it impossible for drivers to assess their own impairment because it creates a false sense of confidence and means drivers are more inclined to take risks and believe they are in control when they are not. For these reasons, the only way for drivers to be safe is to not drink anything at all before driving: feeling sober is not a reliable indication that you are safe to drive.

Learn more: Read our advice for drivers on staying sober and safe.

How much alcohol is in your drink?

The alcohol content of drinks is measured in units. A UK unit is eight grams (or 10 millilitres) of pure alcohol [24]. Below is a list of some popular drinks and how many units they contain: 

  • A single shot (25ml measure) of 40% spirit (e.g. gin, whisky or vodka): one unit
  • A pint of 4.5% beer: 2.3 units
  • A large (250ml) glass of 13% wine: 3.2 units
  • A pint of 6% cider: 3.4 units 

DrinkAware has a unit calculator that you can use to track exactly how much alcohol you have drunk. Apps such as MyDrinkAware can help you keep track of how much you've drunk when out and about.

How long does it take to sober up?

To be safe, drivers should ensure they are completely sober before driving – including the following day.

There’s no way of knowing exactly how long it takes to sober up completely after drinking, but it’s longer than many people think. As a rough guide, drivers should allow at least one hour to absorb alcohol, plus at least one hour for each unit consumed [25] – but it can take longer, so it’s wise to leave extra time to be safe. Our morning-after calculator, at the bottom of this page, shows how long it can take to be alcohol-free after a few drinks.

For example, if you finish drinking three pints of strong lager or one bottle of 12% ABV wine (both nine units) at midnight, you will not be rid of alcohol until at least 9am. If you have a heavy and/or late night drinking you could be impaired all of the next day. Drinking coffee, eating, sleeping and showering don’t make you sober up any faster. It just takes time.

How long it takes for alcohol to leave your system varies depending on lots of factors, including: 

  • Gender – men tend to process alcohol faster than women;
  • Dehydration – if you haven’t drunk enough fluids, alcohol will stay in your system for longer;
  • Mixers – mixing drinks with water and juice means you absorb alcohol slower, fizzy mixers mean you absorb alcohol faster than with no mixers;
  • Tiredness – when you’re tired your liver becomes less efficient, processing alcohol more slowly so it stays in your system for longer. [26]

Brake advises people who need to drive the next day to limit themselves to one or two drinks.

Morning-after calculator

Use this calculator, courtesy of the Morning After drink-drive campaign, to find out roughly how long it can take to sober up from different amounts of alcohol.

Please note, this calculator is not intended to help you work out how much you can drink on a night out before driving home. If you are drinking even one alcoholic drink, you should leave the car at home and make alternative arrangements.

End notes

[1] DfT (2019), Reported road casualties in Great Britain: Provisional estimates involving illegal alcohol levels: 2018

[2] Ibid

[3] DfT (2019), Reported road casualties in Great Britain: Final estimates involving illegal alcohol levels: 2017

[4] Prof. R. Allsop (2015), Saving lives by lowering the drink-drive limit

[5] ibid

[6] DfT (2019), Reported road casualties in Great Britain: Provisional estimates involving illegal alcohol levels: 2018

[7] Prof. R. Allsop (2015), Saving lives by lowering the drink-drive limit

[8] DfT (2019), Reported road casualties in Great Britain: Final estimates involving illegal alcohol levels: 2017

[9] Brake (2017), Direct Line and Brake Survey report 2015-17: Fit to Drive - drink driving and Direct Line and Brake Survey report 2015-17: Fit to Drive – morning after driving

[10] DfT (2019), Reported road casualties in Great Britain: Final estimates involving illegal alcohol levels: 2017

[11] DfT (2019), Reported road casualties Great Britain: 2018, table RAS51018

[12] DfT (2020) Reported drinking and driving, table RAS51102

[13] DfT (2020), Reported drinking and driving, table RAS51010

[14] DfT (2019), Reported road casualties in Great Britain: Final estimates involving illegal alcohol levels: 2017

[15] ETSC (2019), Blood alcohol content (BAC) drink driving limits across Europe

[16] World Health Organization (2015), Global status report on road safety

[17] British Medical Journal (2014),Official blame for drivers with very low blood alcohol content

[18] University of California, San Diego (2011), The relationship between serious injury and blood alcohol concentration

[19] Gov.uk (2014), Being stopped by the police while driving: breath tests

[20] World Health Organization (2018), Random breath testing: data by country

[21] MADD (2012), The impact of implementing random breath testing on criminal justice system resources

[22] World Health Organization (2018), Sobriety checkpoints: data by country

[23] NHS (2018), Risks – alcohol misuse

[24] DrinkAware (2014), What is an alcohol unit?

[25] NHS (2018), How long does alcohol stay in your blood?

[26] Indiana University of Pennsylvania (2012) Blood alcohol level

 Page last updated: March 2020

Tags: Drink-Drive road deaths alcohol