Alcohol can affect your body’s responses making your driving unsafe. This puts you, and others, at risk of accidents.
The safest and best advice is to avoid alcohol completely if you have to drive.
How alcohol affects driving
Many of the functions that we depend on to drive safely are affected when we drink alcohol:
- The brain takes longer to receive messages from the eye
- Processing information becomes more difficult
- Instructions to the body's muscles are delayed resulting in slower reaction times.
You can also experience blurred and double vision, which affects your ability to see things clearly while you are driving. And you’re more likely to take potentially dangerous risks because you can act on urges you normally repress.2
The law and drink drive limits in the UK
What's the drink drive limit in England, Wales and Northern Ireland?
In England, Wales and Northern Ireland, the alcohol limit for drivers is 80 milligrammes of alcohol per 100 millilitres of blood, 35 micrograms per 100 millilitres of breath, or 107 milligrammes per 100 millilitres of urine.3
In most other European countries, the limit is less, usually 50 milligrammes per 100 millilitres of blood.4
What's the drink drive limit in Scotland?
The alcohol limit for drivers in Scotland has been different to the rest of the UK since 2014. The limit is 50 milligrammes of alcohol per 100 millilitres of blood, 22 micrograms of alcohol per 100 millilitres of breath, and 67 milligrammes per 100 millilitres of urine.5
How much can I drink and stay under the limit?
The amount of alcohol you would need to drink to be considered over the driving limit varies from person to person.6
It depends on:
- Your weight, age, sex and metabolism (the rate your body uses energy)
- The type and amount of alcohol you’re drinking
- What you’ve eaten recently
- Your stress levels at the time
Even small amounts of alcohol can affect your ability to drive so the only safe advice is to avoid any alcohol if you are driving.
What is a unit of alcohol?
How would I be tested for drink driving?
If the police want to investigate whether you are over the drink drive limit, they will carry out a screening breath test at the roadside. To do this, they will use a breathalyser.
If you fail this test, or if they have other grounds to believe that your driving was impaired through drink, you’ll be taken to a police station and given a final breath test. At the station you will need to provide two more breath specimens into a complex breathalyser.
The lower of the two readings is used to decide whether you are above the drink driving limit.
The police can carry out a breathalyser test if you have committed a moving traffic offence (such as banned turns or going through a red light) been involved in an accident, or have given the police grounds to believe you are over the limit.
The police are allowed to stop any vehicle at their discretion, and will often set up drink driving check points over periods such as Christmas and New Year’s Eve.
What’s the punishment if I get caught drink driving?
Drunk drivers face a number of penalties depending on the seriousness of their offence. Anyone caught over the legal alcohol limit when driving may be banned from driving for at least 12 months, and face an unlimited fine. You may also be sent to prison for up to six months. Imprisonment, the period of disqualification, size of fine and penalty points depend on the seriousness of the offence.7