Drink driving

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

Drivers who drink-drive are also not able to assess their own impairment because alcohol creates a false sense of confidence. This means that 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.

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.

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. That’s why the only safe amount to drink if you’re driving is nothing at all – not a drop.

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.

Drink-drive rehabilitation courses

Drivers who have been found guilty of drink-driving and who have been banned for 12 months or more may be offered the chance to take a rehailitation course to reduce their driving ban

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 – but it can take longer, so it’s wise to 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 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.