drink driving limits


It’s tempting to have a drink to be sociable at Christmas time, but if you are driving, how confident are you that you know how much you can have and still be below the legal limit?

The legal drink driving limits are:

  • Breath: 35mg of alcohol in 100ml
  • Blood: 80mg in 100ml
  • Urine: 107mg in 100ml

It is impossible to accurately estimate how much alcohol you can consume before you would be above the legal limits. Drinkaware’s chief medical adviser, Dr Paul Wallace observed: “The amount of alcohol in your bloodstream depends on three things: the amount you take in, over what period of time and the speed at which your body gets rid of it.”

As a basic rule of thumb, alcohol is removed from the bloodstream at the rate of about one unit an hour but this varies between individuals depending on gender, age, size, liver function, other medication consumed and metabolic rate.

Nowadays, a standard glass of wine is served in a 175ml glass and is often up to 13% ABV, which adds as much as 2.3 units. A pint glass of beer contains two units if the alcohol content is 3.5%, but most lagers on sale today are much stronger and a pint could easily be 2.8 units. So, it is easy to exceed legal limits without realising.

While you may never consider drinking and driving, studies have found that one in five motorists drive the morning after drinking to excess the night before. Many people believe that a good night’s sleep after drinking and before driving renders them fit to drive but in reality, it is highly possible that you are still over the limit the following morning. Drinking lots of coffee, water or having a big breakfast will not affect the alcohol levels in your system.

It is common knowledge that driving under the influence of alcohol is a criminal offence, but what is less known is that it is also illegal to drive while under the influence of controlled drugs. This can include legally prescribed medication.
The limits set for each drug is different, and for illegal drugs, the limits are extremely low, set at a level to rule out any accidental exposure.
The police can test for certain drugs at the roadside and will arrest those they find above the limits set in law. On conviction, mandatory disqualification will follow.

If you have any questions about legal drink driving limits, please contact Beswicks Legal today.