Section 4 of the 1988 Road Traffic Act
It is illegal to be in charge of a mechanically propelled vehicle, on the road or in a public place, whilst under the influence of alcohol or drugs.
If you have a medical condition which prevents you from giving enough breath for a sample, you must let the police know immediately.
A police officer, who need not be in uniform, can request a breath sample if:
- The police officer has reasonable cause to suspect that you have committed, or are currently committing a moving traffic offence.
- Having stopped, the officer has reasonable cause to suspect that the person in charge of the mechanically propelled vehicle has consumed alcohol.
- The police officer has reasonable cause to believe that you were the person in charge of a mechanically propelled vehicle which was involved in an accident.
NB Failing to provide a roadside specimen is a criminal offence which can result in a maximum fine of £1000, 4 penalty points and possible disqualification.
Allowable alcohol limits in Scotland are:
- 22 microgrammes of alcohol in 100 millilitres of breath or
- 50 milligrams of alcohol per 100 millilitres of blood or
- 67 milligrams of alcohol per 100 millilitres of urine.
The roadside test only confirms you may be over the limit. If you fail this test, you will be taken to a police station and required to give two further specimens, usually of breath, on an
approved instrument. The lower reading must be used. If the reading is over the allowable limit, then you will be charged.
Readings of 41-50 micrograms give an option of replacing breath specimens with blood or urine. Take the opportunity; something such as aftershave may have given a false reading.
The police may request a blood or urine sample if:
- No automatic measuring device is available at the time of your arrest, or it is not working properly.
- The offence involves drugs and the police officer has taken medical advice that your condition may be due to drugs.
- The police officer making the request has reasonable cause to believe that breath samples should not be requested for health reasons.
Road Traffic Act 1988
Drink Driving Laws in the UK