Research has found that 51% of drivers do not know the legal alcohol limit.

The study by insurance comparison site Confused.com, also showed that 31% of drivers did not know that factors such as a person's weight, stress levels, gender, age and whether they have eaten recently mean that alcohol can affect individuals differently.

Rebecca Clough, head of campaigns and communication at alcohol education charity Drinkaware, said: "Even small amounts of alcohol can affect your ability to drive. So the only safe advice is to avoid drinking if you are driving.

"If you are planning to drink when you go out, make alternative arrangements like choosing a 'designated driver' from your group of friends, plan your journey home by public transport or use a licensed taxi."

Gareth Kloet, Confused.com's head of car insurance, said: "My advice is to not drink at all if driving. There is no fool proof way of drinking and staying under the limit. The drink driving limit could be deemed as a myth because alcohol affects everyone very differently.