Do you know your limit?

Police are urging drivers not to drink and drive this Christmas because they believe drivers are not able to judge their own drink drive limit.

Sergeant Mark Steventon said

"Alcoholic drinks have moved on in recent years with alcopops and glasses of wine being served in larger glasses and with stronger beers. We believe people no longer know for certain how much alcohol they have consumed. Often people think they can have a couple of pints or a glass of wine and still be safe. This isn't true at all. The only safe way is not to drink and drive.

One 250ml glass of 13% wine for example is 3.25 units and one pint of 8% beer is 4.5 units.

But what do units mean?

Mark explained

"Working out the number of units of alcohol you have consumed is not a reliable guide because alcohol affects different people in different ways and it also depends how you are feeling. There is no failsafe guide as to how much you can drink and stay under the limit. Units are only useful as a rough guide to make people realise how alcoholic their drinks actually are. Many people kid themselves they can drink 2 pints and be okay.

"The amount and type of alcoholic drink and your weight, sex, age and metabolism will all play their part. 50% of the alcohol in half a pint of beer can be in the bloodstream of an average person within 10 minutes, and all of the alcohol will be absorbed within an hour.

Mark added

"Consuming even a small amount of alcohol will affect your driving. You don't judge speed and distance so well and your reactions are not as fast.

"We would urge revellers to use taxis, booking them in advance rather than leaving it to chance on the night, public transport or make arrangements for one of your group to be a nominated driver."

Police are able to precisely measure the amount of alcohol consumed. The limit is 35 micrograms of alcohol per 100 millilitres of breath or 80mg per 100ml of blood.

On a Saturday night out drinking, by midnight you may have a blood alcohol level of 200mg/100ml. If you get up at 7.30am this will have dropped to around 90mg/100ml and you will still be over the legal limit. By midday you will be down to around 20mg/100ml and under the legal limit but your driving may still be affected and you could be guilty of an offence

In 2003 19% of drivers killed in Great Britain, whose blood alcohol level was known, were over the legal limit and young male drivers are significantly over-represented in the drink-drive accident statistics

The minimum penalty for drinking and driving is a one year driving disqualification. But if you are brought before a Magistrate, you could receive a lifetime ban and a fine of up to £5000. If prosecution takes place in a Crown Court the Judge could impose a prison sentence of up to 10 years. Fines given by a Judge have no upper limit.

How to work it out

Multiply the volume/amount of drink in milliltres by percentage ABV, then divide by 1000. For example with a 175ml glass of wine at 13% ABV 175 (amount) X 13 (%ABV) = 2,275 Divided by 1000 = 2.275 ie 2.3 units Now let's take 1 pint of strong lager at 8% ABV 1 pint (568ml) X 8 = 4544 Divided by 1000 = 4.544 ie 4.5 units