Driving Under the Influence of Drugs

Driving Under the Influence of Drugs

Lustitia Law provide legal advice and representation in all cases related to driving under the influence of drugs.

An allegation of driving whilst unfit under the influence of drugs can be brought if the Police have reason to believe that you were driving a motor vehicle on the road or in a public place after consuming drugs. This can include drugs that are legal as well as those that are illegal.

To determine whether you are unfit to drive a vehicle, the Police will carry out a field impairment test. If you fail this test you may be taken to the Police station to undergo biological tests such as blood or urine samples. It is an offence to refuse to participate in any of these tests, either at the Police Station or on the roadside.

The allegation of drug driving is an extremely serious one and could lead to a custodial sentence. Our specialist team of solicitors will review the strength of the prosecution’s case against you and advise you on the merits of your case. Prosecutions for drug driving offences are restricted to those where Police can prove that an individual is incapable of driving because of drugs.

Our solicitors are available to discuss your individual case, by providing immediate advice, representation and assistance during legal proceedings and ensuring the best interests of our clients.

Please contact us on 01274 271505 or email


Drug Driving Law in England & Wales

The new rules that came into effect in March 2015 driving under the influence of drugs sought to make it easier to successful prosecute drug driving. Section 56 of the Crime and Courts Act 2013 took inspiration from the offence of driving under the influence of alcohol, by introducing prescribed limits for certain illegal and prescription drugs. Under the new law, there is no requirement to prove the driver was impaired, only that the level of drugs in the driver’s body exceeded the legal limit.

The roadside procedure was also amended in an attempt to make it less vulnerable to challenge. Dräger devices – or ‘drugalysers’, as they are often referred to – can be used at the roadside to obtain evidence of drug taking.

the use of so-called ‘drugalysers’ is concerning, considering they are only capable of detecting two of the 16 drugs covered by the new law. This means much of the roadside procedure remains the same as it did before the 2015 legislation came into effect: subjective and slow.


At Lustitia Law, our experience, exceptional reputation and robust attitude means we have areas of concern with the implementation of the new procedure.

Section 56 of the Crime and Courts Act 2013 and the accompanying Regulations make it an offence to drive if you have certain levels of drugs in your system, regardless if your driving is not impaired. The prescribed limits set out in the Regulations include both legal and illegal drugs, for example diazepam, morphine, cocaine and cannabis. The limits for each drug are very low; in essence, it is a zero tolerance approach.

The current 2015 law has 16 specified drugs (eight illegal and eight prescription), you can now be charged with drug driving based on the results of a blood test (or even a mouth swab) alone.

‘Illegal’ drugs threshold limit in blood

benzoylecgonine – 50µg/L

cocaine – 10µg/L

delta-9-tetrahydrocannibinol (cannabis) – 2µg/L

ketamine – 20µg/L

lysergic acid diethylamide – 1µg/L

methylamphetamine – 10µg/L

MDMA – 10µg/L

6-monoacetylmorphine (heroin) – 5µg/L


‘Medicinal’ drugs threshold limit in blood:

clonazepam – 50µg/L

diazepam – 550µg/L

flunitrazepam – 300µg/L

lorazepam – 100µg/L

methadone – 500µg/L

morphine – 80µg/L

oxazepam – 300µg/L

temazepam – 1,000µg/L


The introduction of these limits has not meant that the old test no longer applies and a person can still be charged if they are found to be under the ‘limit’ but are deemed unfit to drive.

Under the current 2015 legislation, it is only necessary to prove that the level of drugs in the driver’s system exceeds the legal limit.

At the roadside, if the police suspect a person is driving while under the influence of drugs, they can stop the person and carry out a field impairment assessment (FIT) and/or use a Home Office approved Dräger device to test for the presence of certain drugs. If, after testing, the officer believes the driver is unfit to drive because of drugs, they will arrest the person and take them to the police station, where they will be required to provide a blood or urine sample. The blood or urine taken must be split into two, and one sample given to the driver in case they wish to conduct an independent test.

The penalties for drug driving include

 – mandatory driving disqualification of a minimum of 1 year

– fine up to £5,000

– up to 6 months in prison and, a criminal record.

Your driving licence will also show that you have been convicted for drug driving and this will last for 11 years.

Also depending on the circumstances, the court may also impose the following penalties:

– Community order

– Extended retest

If you have previously been convicted of the offence of driving under the influence of drugs in the last ten years, disqualification from driving may be extended to 36 months