Drink Driving: What you need to know

Last updated September 2 2021

Across the world, it is illegal to drive after you’ve drunk a certain amount of alcohol. Whilst the limit varies, the general message is the same – you shouldn’t drink and drive.

Any amount of alcohol can impair your senses and give you the potential to cause harm to yourself and others on the road. So, the safest bet is to avoid driving altogether if you’ve drunk alcohol, no matter how little it may be.

Value your car in under 30 seconds

What is drink driving?

Drink driving refers to operating a motor vehicle whilst the level of alcohol in your blood is over the legal limit set by the government.

However, drink driving can also be taken to mean driving under the influence of any alcohol, regardless of the legal limit. It can sometimes be called driving under the influence (DUI) or driving while intoxicated (DWI) depending on where you are in the world.

It is a legal offence to drive, attempt to drive, or be in charge of a motor vehicle on a road or public space if the level of alcohol in your breath, blood or urine exceeds the prescribed limit, according to UK law.

The penalty for breaking this law will be decided by the magistrates who will hear the case in court.

How does alcohol affect driving?

Alcohol is a depressant, so even the smallest measures can affect reaction times, judgement and coordination. It can also make you drowsy, affect your vision and how you are capable of judging speed and distance.

Drivers who drink-drive are also incapable of assessing their own impairments because alcohol creates a false sense of confidence. Because of this, drivers may be more inclined to take risks and believe they are in control when the reality is to the contrary.

Feeling sober isn’t a reliable indication that you are safe to drive, so it’s best to avoid drinking altogether before getting behind the wheel.

Drink driving statistics

According to research by Brake:

  • In the UK, more than 200 people die every year in a drink-drive related crash
  • You are 6 times more likely to be involved in a fatal crash if you have 50-80mg alcohol per 100ml of blood, compared to 0ml
  • You are 3 times more likely to die on the roads if you have 20-50mg alcohol per 100ml blood, compared to 0ml
  • You’re 46% more likely to be at fault in road collisions if you have 10mg per 100ml.

What is the legal UK drink-drive limit?

In the UK, the legal limit differs slightly depending on where you are located.

If you are in England, Wales or Northern Ireland, the legal alcohol limit for drivers is as follows:

  • 80 milligrammes of alcohol per 100 millilitres of blood
  • 35 micrograms per 100 millilitres of breath
  • 107 milligrammes per 100 millilitres of urine.

In Scotland, these limits are much lower:

  • 50 milligrammes of alcohol per 100 millilitres of blood
  • 22 micrograms of alcohol per 100 millilitres of breath
  • 67 milligrammes of alcohol per 100 millilitres of urine.

In fact, the UK (except for Scotland) has the highest alcohol limit in the whole of Europe.

Drink driving laws and penalties

As we’ve already mentioned, it is a criminal offence to drive while above the legal drink driving limit and you will be punished accordingly.

A drink driver is assessed by obtaining a sample of their breath, blood or urine, which is tested to the requirements above. If a person is found guilty of drink driving, they can be fined, banned from driving or even imprisoned in serious cases.

These punishments are dependent on the severity of the offence, which according to gov.uk include:

  • Being in charge of a vehicle while above the legal limit or unfit through drink – this could result in three months’ imprisonment, up to £2500 fine and a possible driving ban
  • Driving or attempting to drive while above the legal limit or unfit through drink – a person could get six months’ imprisonment, an unlimited fine and a driving ban for at least one year (this could be 3 years if the person is considered a high-risk offender)
  • Refusing to provide a specimen for analysis could lead to six months imprisonment, an unlimited fine and a driving ban for at least a year
  • Causing death by careless driving under the influence of drink – this could result in 14 years imprisonment, an unlimited fine and a ban from driving for at least 2 years.

In Scotland, these limits are much lower:

You are identified as a high-risk offender if:

  • You have been convicted of two drink driving offences within 10 years
  • You were driving with an alcohol reading of at least 87.5mg of alcohol per 100ml breath, 200mg of alcohol per 100ml blood, or 267.5mg of alcohol per 100ml urine
  • You refused to give the police a sample of breath, blood or urine to test for alcohol
  • You refused to allow a sample of your blood to be tested (e.g., if the blood was taken when you were unconscious).

How is a drink-driver tested?

The police are within their rights to stop any vehicle at their discretion, and they can test you on the roadside to check the amount of alcohol in your system. If the police want to investigate whether you are over the drink drive limit, they will carry out a screening breath test with a breathalyser.

Should you fail this test, or the police have other grounds to believe your driving was impaired through drink, they will take you to a police station and give you a final breath test. At the station, two more breath specimens will need to be provided into a complex breathalyser.

The lower of the two readings is used to decide whether you are above the legal limit. Other specimens, blood and urine samples, may be required; if they are requested, you are legally obligated to provide them and the penalties for refusal are outlined above.

A breathalyser test can be carried out if you have committed a moving traffic offence, such as a banned turn or going through a red light, been involved in an accident or have given the police other reason to believe you may be over the limit.

Over periods where people are more likely to drink drive, such as Christmas and New Year’s, there may be checkpoints set up on busy roads to spot check drivers.

How is a drink-driver tested?

This is a commonly asked question and comes in a few variations: can I drink a glass of wine and drive? How many drinks is too many? And so on.

In the UK, the alcohol content is measured in units. A UK unit is eight grams (or 10ml) of pure alcohol.

For reference, here is the alcohol content of some popular drinks:

  • A single shot (25ml) of a 40% spirit (such as gin or whiskey) is one unit
  • A pint of 4.5% beer is 2.3 units
  • A large (250ml) glass of 13% wine is 3.2 units
  • A pint of 6% cider is 3.4 units.

A general conception is that two average pints of lager or two small glasses of wine would put you over the legal limit.

However, every person’s alcohol tolerance is different and what might be fine for one person isn’t for another. The amount of alcohol that it takes to send someone over the limit is entirely circumstantial and personal.

Factors like weight, age, sex and metabolism all come into play when it comes to whether you would be over the drink drive limit. The type and amount of alcohol you drink, what you’ve eaten that day and even your stress levels at the time can also determine the effects of alcohol on your body, as well as the limit in your bloodstream.

Even the smallest amounts of alcohol (i.e a half-pint) can affect your ability to drive, so it’s advised to avoid drinking entirely when you know you are going to drive.

How to assess your fitness to drive the day after drinking

We’ve established that the only truly safe way to stay under the legal limit of alcohol is not to drink at all, but what about the day after?

You need to make sure you are fully sober before driving again, but there isn’t a sure-fire way of knowing how long your body will take to sober up. However, the length of time it does take is longer than people may think.

As a rough guide, drivers should allow at least one hour to absorb alcohol plus at least one hour for each unit consumed. For example, if you drank three large glasses of 13% wine at midnight, you may not be rid of alcohol until at least 10am. It can take much longer than this, so be sure to leave some extra time just in case.

If you have a heavy or late-night drinking, you could find yourself impaired all the next day. Drinking coffee, eating, sleeping and showering doesn’t help you to sober up any faster, instead it just requires time.

The length of time that alcohol takes to leave your system varies. For example, men tend to process alcohol faster than women. Dehydration can be a big factor, as well as the mixer you chose when you were drinking. Water and juice will help you to absorb alcohol more slowly than if you drink it straight, whereas fizzy drinks can cause you to absorb it more quickly.

Tiredness can also play a huge role, as when you’re tired your liver becomes less efficient. As with drinking and driving on the night, to be fully safe you should avoid drinking altogether if you know you have to drive the next day.

Consequences of drink driving

Being convicted of driving under the influence has numerous effects that go beyond legal repercussions – in fact, it can impact your daily life.

You could potentially lose your job, particularly if you drive for work. Your employer will be able to see any offences you have against your licence. Following an offence, you will have a criminal record, which may make it difficult to seek employment in the future.

If, or when, you’re legally allowed to drive again, car insurance costs could increase significantly after a drink-driving conviction. As with any other criminal record, you might even find it difficult to enter other countries (such as the USA) and this can affect plans for taking holidays, working or studying abroad.

Worse yet, every time someone drinks and drives, they gamble with the safety of others on the road, including their own. Drink-driving could cause a serious accident, and you could potentially cause injury, or worse, death, to yourself and others.

This is why it’s extremely important to think before you decide to drink and drive because the consequences go much further than points on a licence and a hefty fine.

How to avoid drink driving

When you know you are going out to drink, you should arrange to have a designated driver for the evening. A designated driver is someone who is happy to abstain from alcohol in order to drive everyone home safely. Where this isn’t available, use public transport or book a taxi.

If you need to drive somewhere, drink soft drinks, mocktails or zero-percent alcohol beers instead of alcoholic versions. Or try an alternative to pubs and clubs altogether and enjoy an alcohol-free night out instead.

How to report a drink-driver

Whilst you may be sensible, someone else might not be. Talking someone out of drink-driving may not be the safest option, so don’t approach someone you feel may become aggressive or violent. If you see a drunk person about to drive, call the police.

You might need to supply the vehicle’s registration number and a description, such as the colour and make. You should also give a description of the driver as well as their address if you know it. Other useful information can include the place they were drinking, or where they appear to be driving to.

If you want to report a drink-driver after the driving has already taken place, call the police on 101, or Crimestoppers anonymously on 0800 555 111.