Technically the police are not allowed to do random breath tests. They should only happen if the person has committed an offence, been involved in an accident or if the police have reason to believe that the driver is over the alcohol limit.
The test is administered by the driver being asked to blow into a device with a traffic light type of display. If the display is red then you will be taken to the police station where a further two test will be taken using equipment with a scale showing the number of microgrammes per 100 millilitres. If you cannot or will not blow into the bag you will be taken to the police station.
Although the legal limit is 35 micrograms you may not be prosecuted if you are below 40 micrograms, but do not rely on this. If you are between 40 and 49 micrograms you will be offered the alternative of a blood or urine test. You've got little to lose by taking this option and may just strike lucky with a lower reading!What is the Penalty for Drink Driving (being over the limit)?
The penalty for drink driving is a mandatory one year disqualification and fine usually of around £400. There is some discretion where the disqualification would stop someone from earning a living or if it was a genuine emergency. The maximum sentence for drink driving is a 6 month prison sentence and £5000 fine. The penalty will be higher if other offences were committed at the same time. Bigger penalties are imposed for second and subsequent offences.What if the car wasn't moving?
The offence is of "being in charge of a vehicle..." and so you do not have to even have the engine running!
A number of breath test devices are available to help you test your own alcohol level. Although they can be helpful, such devices have no legal force and should not be relied on. Responsible drivers don't drink and drive.
If you are caught drinking and driving you are advised to consult a lawyer. These pages are for information only and are not intended to be relied on in the case of any drink driving or other offence.
DON'T DRINK AND DRIVE!