If you take drugs and drive you may be guilty of the following offences:
- being unfit to drive through drink or drugs;
- being over the prescribed limit in relation to the levels of specified drugs in your blood – you can commit this offence even if your driving is unaffected by the drugs.
In relation to both offences, if the police suspect you have been taking drugs and you are driving, attempting to drive or are in charge of a mechanically propelled vehicle (offence 1) or a motor vehicle (offence 2) on a road or public place, they have the power to require you to take a field impairment assessment or drug test.
A field impairment assessment consists of a series of tests e.g. touching the tip of your nose with the tip of your finger whilst your eyes are closed, that are designed to see if drugs are affecting your ability to drive properly.
A drugs test uses a specimen of sweat or saliva to detect the presence of drugs. If you –
- perform poorly in the field impairment test, or
- give a positive drugs test, or
- you fail/refuse to take either test and the police officer suspects drugs,
you can be arrested and taken to a police station.
At the police station, further tests and medical examinations may be carried out and you could ultimately be prosecuted for being:
- Unfit through drugs – note there are no lists of specified drugs or set levels in relation to this offence, but the police must prove that you are unfit to drive. Unfit means that your ability to drive properly is for the time being impaired.
- Over the prescribed limit in relation to specified drugs – note there are specified drugs and set levels in relation to this offence – see the table below.
The table below specifies the controlled drugs and, in each case, the limit in blood for the offence of being over the prescribed limit in relation to specified drugs.
| Controlled drug |
Limit (microgrammes per litre of blood) |
| Amphetamine |
250 |
| Benzoylecgonine |
50 |
| Clonazepam |
50 |
| Cocaine |
10 |
| Delta-9-Tetrahydrocannabinol |
2 |
| Diazepam |
550 |
| Flunitrazepam |
300 |
| Ketamine |
20 |
| Lorazepam |
100 |
| Lysergic Acid Diethylamide |
1 |
| Methadone |
500 |
| Methylamphetamine |
10 |
| Methylenedioxymethamphetamine |
10 |
| 6-Monoacetylmorphine |
5 |
| Morphine |
80 |
| Oxazepam |
300 |
| Temazepam |
1000 |
The units of the thresholds are µg /L or micrograms per litre - it's important to realise that even relatively small amounts of the drugs can put you over the threshold. If you’re caught driving, attempting to drive or in charge of a vehicle with levels of illegal drugs above those shown in the table, you will commit an offence.
Defences
Unfit through drugs – in charge defence
It is a defence for a person to prove that at the time they are alleged to have committed the offence, there was no likelihood of them driving the vehicle while unfit. However, in determining whether there was such a likelihood, the court may disregard any injury to them and any damage to the vehicle.
Over the prescribed limit in relation to specified drugs – medical defence
It’s a defence for a person to prove that the:
- drug was provided for medical or dental purposes;
- drug was taken in accordance with any directions given by whoever prescribed the drug and in accordance with the manufacturer’s directions; and
- possession of the drug immediately before taking it was not unlawful.
Over the prescribed limit in relation to specified drugs – in charge defence
It’s a defence for a person to prove that at the time they are alleged to have committed the offence the circumstances were such that there was no likelihood of them driving the vehicle whilst the proportion of the specified controlled drug in their blood remained likely to exceed the specified limit for that drug. However, in determining whether there was such a likelihood, the court may disregard any injury to them and any damage to the vehicle.
If you’ve been prescribed medication that contains any of the drugs listed in the table or if you are unsure about whether your medication contains any of these drugs, you should talk to your doctor/dentist/health care professional about whether it's alright for you to drive – you can still drive after taking the medicinal drugs listed in table if:
- you've been prescribed them and are following medical advice on how to take them;
- they aren't causing you to be unfit to drive, even if you're above the specified limits.
Note that the police cannot give any advice on the dosage that would put you over the specified limits or how long after taking a drug you must wait before you a safe to drive. The reason for this is that there are just too many variables, everyone metabolises drugs differently and factors such as your height, weight and what you have had to eat will all play a part.
Penalties
The penalties for drug driving are:
- A minimum of a one year driving ban
- An unlimited fine
- Up to six months in prison
- A criminal record
