The new drug driving law came into force on 2 March 2015.  The law is very similar to that of drink driving, except of course this is drug driving. The offences are only committed if the drug driving is on a road or public place.

Before March, the only offence which could have been proceeded with if a person was found to be driving with drugs in their system, was ‘driving whilst unfit through drugs’. However, this required the prosecution to show that the drugs actually impaired the person’s ability to drive. This new law creates a strict liability drug driving offence so that an offence is committed if the person is over the prescribed limit, regardless of whether there is any driver impairment. This brings it in line with drink driving.

The Drug Driving (Specified Limits) (England and Wales) Regulations 2014 create a new section (5A) within the Road Traffic Act 1988 which specifies limits for certain controlled drugs. An offence is committed if a person is driving, attempting to drive or in charge of a vehicle with a level of drugs in their blood or urine which is above the prescribed limit.

You may have a defence to drug driving if you are using a prescription drug and can show that the following apply:

(a) the specified controlled drug had been prescribed or supplied to you for medical or dental purposes,

(b) You took the drug in accordance with any directions given by the person by whom the drug was prescribed or supplied, and with any accompanying instructions (so far as consistent with any such directions) given by the manufacturer or distributor of the drug, and

(c) Your possession of the drug immediately before taking it was not unlawful.

(a) your actions were contrary to any advice, given by the person by whom the drug was prescribed or supplied, about the amount of time that should elapse between taking the drug and driving a motor vehicle, or

(b) your actions were contrary to any accompanying instructions about that matter given by the manufacturer or distributor of the drug.

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
Illegal’ drugs (‘accidental exposure’ – zero tolerance approach) Threshold limit in blood (µg/L)
benzoylecgonine 50
cocaine 10
delta-9-tetrahydrocannibinol (cannabis) 2
ketamine 20
lysergic acid diethylamide 1
methylamphetamine 10
6-monoacetylmorphine (heroin) 5