Many riders believe they are safe to drive if they are below the legal limit. They are wrong.

You do not need to be a drunk driver to be a danger on the roads. The risk of being in an accident increases in direct proportion to the amount of alcohol consumed. As alcohol impairs the functions of the brain, even one drink will impair your riding ability.

It is a serious offence to drive, attempt to drive, or be in charge of a motor vehicle when the level of alcohol in the blood exceeds 80 milligrammes of alcohol per 100 milli-litres of blood; or the level of alcohol in urine exceeds 107 milli-grammes per 100 milli-litres.

It is a serious offence to fail to provide a sample of breath, blood, or urine, or to refuse to accompany a Garda.

MAG Ireland very strongly disapproves of and actively discourages the practice of driving under the influence of alcohol or other drugs whose use while driving has been proven to be unsafe.

Alcohol Level: 20mg – 50mg

Your judgement of distance and speed of oncoming vehicles is affected. You will tend to take greater risks, particularly in dangerous manoeuvres such as overtaking or driving too close to the car in front.

Alcohol Level: 50mg – 80mg

Your vision is affected, slowing your reaction to red lights and tail-lights. You are more likely to drive too fast and to misjudge distances when approaching a bend. You will find it difficult to ride in a straight line.

Alcohol Level: 80mg +

You will overestimate your own ability. Your vision is so affected you may not notice cyclists, pedestrians or parked cars in sufficient time to avoid them.

A ‘unit’ of alcohol is a half-pint of beer or a small measure of spirits or a glass of wine or sherry. The effect on the individual varies considerably, so it is impossible to give absolute guidelines.

Example 1

A male weighing 80 kgs consumes 1 litre of beer with an alcohol content of 5%.

In a male, body fluid is approximately 70% of body weight. This man, therefore, has 56kgs of body fluid. The weight of the alcohol consumed is 40 grammes (one milli-litre of alcohol weighs 0.8 grammes). The alcohol level is determined by dividing 40 by 56, giving 0.71. This means a blood alcohol content of "0.71 grammes per kilogram", or "71 milligrammes per 100 milli-litres."

Example 2

A female weighing 55 kgs consumes 1 litre of beer with an alcohol content of 5%.

In a female, body fluid is approximately 60% of body weight. This woman, therefore, has 33kgs of body fluid. The weight of the alcohol consumed is 40 grammes (one milli-litre of alcohol weighs 0.8 grammes). The alcohol level is determined by dividing 40 by 33, giving 1.21. This means a blood alcohol content of "1.21 grammes per kilogram", or "121 milligrammes per 100 milli-litres."

Blood alcohol level is determined by a number of factors

• Type of drink and amount
• Gender
• Weight and constitution
• Individual drinking habits
• Whether food has been consumed

The same amount of alcohol consumed will result in different blood alcohol levels for different people.

Alcohol is eliminated from the system at a rate of about one unit each hour. If you have had a lot to drink the night before, your blood alcohol level may still be in excess of the legal limit the following morning.

Contrary to belief, the elimination process cannot be speeded up by drinking tea or coffee. Counting units and trying to estimate your blood alcohol level is unreliable.

A maximum fine of £1000 and/or a maximum of 6 months imprisonment may be imposed on conviction. The amount of any fine and/or the term of imprisonment are entirely at the discretion of the court.

Automatic disqualification from driving applies to all drink-driving convictions. The minimum period depends on the alcohol levels in individual cases.

Mandatory disqualification periods of 1 year, or more, may subsequently be halved by a court. A period of 3 or 6 months may not be reduced.

This information sheet is provided free of charge as a service to motorcycling. MAG Ireland cannot accept any responsibility or liability for any errors or omissions. Last updated 2001-02 Approved by NEC: 2001-03