Drink driving is still one of the biggest killers on our roads. One in seven UK road deaths result from drink drive crashes where the driver was over the limit [1].

These deaths, and the many more serious injuries, can be stopped if all drivers pledge to not drink a drop before driving. They can also be stopped by improving government policies. 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.

The effects of alcohol

Alcohol is a depressant drug and even small amounts (such as half a pint of lager) affect drivers’ reaction times, judgment and co-ordination. 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.

It is also impossible to calculate how much alcohol you have in your blood (even if you know exactly how much you have consumed), or how long it will stay in your system. The speed at which alcohol is absorbed into your system (and how quickly your system gets rid of it) depends on a large number of factors, including your sex, weight, metabolism, health and when you last ate. Read about the alcohol content of different drinks here.

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 you should allow at least one hour to absorb alcohol, plus at least one hour for each unit consumed - but it could take longer, so you should always leave extra time to be safe. For example, if you finish drinking three pints of strong lager or one bottle of 12% ABV wine (both nine units) at 11pm, you may not be rid of alcohol until at least 9am, but it could take much longer depending on factors such as your weight.

Drinking coffee, eating, sleeping and showering don’t make you sober up any faster. It just takes time.

Our messages for drivers:

• Never drink any amount of alcohol if you’re driving
• Never drink if you’re driving early the next morning
• Plan ahead to make sure you can get home safely when going out for the night,  using public transport, booking a taxi, or having a designated driver who sticks to soft drinks 
• Take responsibility for others: never buy a drink for someone who is driving

Drink drive casualties and behaviour in the UK

In the UK, drink-drive casualties (deaths, serious injuries and minor injuries) decreased significantly during the 1980s, but rose by nearly a third between 1993 and 2002 (from 14,980 to 20,140). Since then they have been falling, but remain one of the biggest killers on our roads.

Many more drink-drive crashes are caused by drivers who only have small amounts of alcohol in their blood. A further estimated 65 road deaths per year are caused by drivers who are under the drink-drive limit, but who have a significant amount of alcohol in their blood [2].

According to a survey of 1,000 drivers by Brake, the road safety charity, half of UK drivers admit to drink-driving (after drinking any amount of alcohol at least once in the last 12 months). More than one in four drivers (28%) also admit driving the morning after having a lot to drink, when they are likely to still be over the limit.[3]

The worst offenders

Certain types of driver are more likely to drink-drive than others:

• Male drivers - the vast majority of convictions for dangerous driving while under the influence of alcohol (about nine in 10) are against men [4]
• Occupational drivers - in Brake’s survey of 1,000 UK drivers, drivers who drive for work were more likely to admit drink-driving (driving after drinking any amount of alcohol, at least once in the previous 12 months) than other drivers (57% compared to 43%) [5]
• Car drivers are most likely to fail a breath test, followed by motorbike riders [6]
• Young drivers aged 17-24 have the highest level of drink-drive crashes per distance travelled [7].

The law - the drink-drive limit

Drink drive limits vary between nations but can be as low as 20mg of alcohol per 100ml, which is effectively zero tolerance. The current drink-drive limit in the UK is 80mg of alcohol per 100ml of blood, significantly higher than the majority of EU countries (the EC recommends a limit of 50mg of alcohol per 100ml of blood or less). Research shows that a driver's judgement and motor skills are affected when they are still well below this limit.[8]

In September 2011, Northern Ireland announced it would cut its drink drive limit to 50mg alcohol per 100ml blood, with a lower limit of 20mg alcohol per 100ml blood for novice drivers and those who drive for a living. Read more. In 2012, Scotland also announced plans for a 50mg limit. 

Charges and penalties

In the UK if a driver is found to be either over the drink-drive limit, and/or driving while impaired by alcohol, they can receive a maximum penalty of six months in prison and an unlimited fine. Anyone convicted must also receive a one-year disqualification. If a driver kills someone while under the influence of alcohol, they can be charged with death by careless driving while under the influence of drink or drugs, which carries a maximum penalty of 14 years in prison.

Read about Brake's 'not a drop not a drag' campaign, calling for action on drink and drug driving by the UK Government.

[1] Reported Road Casualties Great Britain 2011: Annual Report (Department for Transport, 2012)
[2] Reducing the BAC limit to 50mg - what can we expect to gain?, Professor Richard E Allsop, Centre for Transport Studies, University College London (PACTS, 2005)
[3] The Green Flag Report on Safe Driving 2004: Part one, Fit to Drive? (Brake, 2004)
[4] Motoring Offences and Breath Test Statistics - England and Wales 2002 (Home Office)
[5] Alcohol and the workplace (Institute of Alcohol Studies, 2003)
[6] The Green Flag Report on Safe Driving 2004: Part one, Fit to Drive? (Brake, 2004)
[7] Road Casualties Great Britain 2010: Annual Report (Department for Transport, 2011)
[8] The relationship between serious injury and blood alcohol concentration, University of California San Diego, 2011