Drugs, Drug Driving Offences and The law

It used to be the case that the police could only charge you with driving whilst under the influence of drugs.

On the 2 March 2015, legislation came into force making it illegal to drive with certain levels of drugs in your system.

Section 56 of the Crime and Courts Act 2013 inserted s.5A into the Road Traffic Act 1988 making it an offence to drive with a blood concentration in excess of a specified limit for a specified controlled drug.

Further regulations on amphetamine came into force on 14 April 2015.

Drug-Drive offence Code: DR80 offence code

Drug Driving Penalties:

  • 12 Month Minimum Ban
  • An Unlimited Fine
  • Up To 6 Month Prison Sentence
  • A Criminal Record
  • Community Orders
  • Custody

See Drugs Sentencing Guidelines

Illegal drugs

The government have taken a ‘zero-tolerance’ approach in relation to the legal limits for illicit substances which means even trace amounts could lead to a prosecution.  The prosecution does not have to prove the driver is impaired or that their ability to drive is affected by the drug.

  Limit µg/L
Cocaine   10
Cannabis (THC)   2
LSD   1
Ketamine   20
Ecstast / MDMA   10
Heroin & Diamorphine   5
Methylamphetamine   10
Benzoylecgonine (by-product of cocaine)   50
Amphetamine   250
Controlled Drugs    
Morphine   80
Methadone   500
Diazepam   550
Clonazepam   50
Flunitrazepam   300
Lorazepam   100
Oxazepam   300
Temazepam   1,000

These can be either prescription or over-the-counter medications. Unlike illegal substances the limits are set at levels where there is an increased risk of road traffic collision and are higher than would be expected in someone who has taken a normal dose as medicine.

How do these drugs affect the ability to drive?

If you want to know more about the impact each of these drugs has on your driving, please click here

How Long Do Drugs Stay in Your System?

The time required for each type of drug to leave your system varies greatly depending upon several factors including the amount and specific type of exact drug consumed, how it is taken, the biological makeup of the user and consumption of other substances (such as alcohol) at the same time.

The government has intentionally not provided any guidance for drug detection times. While absorption rate will vary greatly from person to person due to your height, weight and metabolic rate, approximate times needed for your body to flush each drug type are indicated below.

Typical Time Limits for Commonly Used Drugs    
Delta-9-Tetrahydrocannibinol - Cannabis   48 - 72 hours (Up To 10 Weeks for Chronic Users
Cocaine   12 - 72 Hours
Methylenedioxymethamphetamine - MDMA   24 - 96 Hours
6-Monoacetylmorphine - Heroin   48 - 120 Hours
Ketamine   48 - 96 Hours
Lysergic Acid Diethylamide - LSD   24 - 72 Hours
Methylamphetamine - Crystal Meth   24 - 96 Hours

What if the drug was prescribed to me?

s.5A(3) provides a defence if a person charged with an offence under this section can show the following:-

That the specified controlled drug had been prescribed or supplied for medical or dental purposes, the drug was taken 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 that the possession of the drug immediately before taking it was not unlawful under section 5(1) of the Misuse of Drugs Act 1971 (restriction of possession of controlled drugs).

What I am at risk of?

The sentencing guidelines for this offence were revised on the 1st July 2023 bringing the sentencing assessment criteria in line with drink driving.  This involves assessing the circumstances of the offence and considering the factors which increase culpability and harm. 

Please see new sentencing guidelines

This is problematic as the new guidelines state that if there are obvious signs of impairment or any evidence of an unacceptable standard of driving then the magistrates will consider imposing a 17-to-28-month disqualification and community orders.  As with any new guidance we are going through a phase of uncertainty in relation to the potential length of a disqualification.

What happens when I am stopped?

If you are stopped by the police for any road traffic offence the police have the authority to request preliminary specimens of breath and saliva.  Only a police constable in uniform can require a person to submit to a preliminary test.

There are currently only two preliminary (road side) drug testing devices which have received type approval by the Secretary of State (Home Office), these are:

  • The Draeger DrugTest 5000, this device is designed to detect delta-9-tetrahydrocannabinol (THC, the main active ingredient of cannabis) only; and
  • The Securetec DrugWipe 3S S303G, this device is designed to detect delta-9-tetrahydrocannabinol (THC, the main active ingredient of cannabis) and cocaine.

In our experience the drug wipe test gives a positive result for other Class A drugs as well.

If you appear to be impaired, even if you pass a preliminary test, you may also be required to undertake a field impairment test. Which could involves assessing pupil dilation, standing on one leg, walk and turn, finger to nose and balance & judgement tests (Romberg test). If you are deemed to have failed one or more of these roadside impairment tests, you will be taken to a police station to be blood tested.

You should be provided with your own part of the specimen to take with you.  Keep your blood sample refrigerated and call Patterson Law.

The blood tests take three to four months to process and if you are charged then what? You will be going to Court and will face a mandatory minimum 12-month disqualification.

Being in charge of a motor vehicle with a specified drug above the specified limit

The 'in charge of a vehicle' offence normally occurs when you get caught sat in your car with the keys while you are over the specified limit in drugs. 

The offence has similar sentencing guidelines to being drunk in charge of a vehicle and carries the risk of 10 points,  a community order and a discretionary ban if you are caught.

In charge Offence Code: DG40

In Charge While Over the Limit Penalties:

  • 10 Penalty Points
  • Discretionary ban
  • A criminal record
  • Community Orders
  • Custody

You can defend this allegation if you can convince the court that you wouldn't have driven until the substance in your system had reduced below that of the legal limit.   It is likely you will require a pharmacologists' report to show how long it would have taken for the substance to reduce below the limit. 

What To Do If You Are Stopped By The Police?

It seems a huge proportion of drivers who are stopped do have illegal substances in their system.

We can help if you are stopped by the police on suspicion of a drug driving offence.

We have found that the police often making procedural mistakes in relation to taking mouth swabs and blood samples at the station. This will often create the potential to defend allegation.

There is also an opportunity to avoid disqualification by arguing special reasons, especially in relation to prescribed drugs.

Most people we speak to are unfamiliar with the legislation / police procedures and will often not realise that there is a potential defence / special reasons argument to avoid disqualification.

We need to speak to you directly to assess your prospects of success if you have been caught drug driving.