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A change in the law (first in England and Wales and later extended in Scotland) means that it is illegal to drive if you have certain levels of cannabis in your blood, even if you consider that your driving is not impaired. This is a shift away from the old offence of driving whilst unfit through drugs where the onus was on the police to prove there was a level of driver impairment while under the influence.

The change in drug driving laws has meant there has been an increase in arrests and convictions for being caught smoking weed and driving, purely on the basis that motorists are over a specified legal limit. Regardless of how competent the driver may feel driving after smoking cannabis, that is simply no longer an adequate defence these days.

The law doesn’t cover Northern Ireland but you can still be arrested there if you’re considered unfit to drive.

What happens if I am caught driving after smoking cannabis?

If the police stop you on suspicion of driving after smoking weed, they may ask you to take a ‘field impairment assessment’.This will consist of various tasks – such as walking in a straight-line, balancing on one leg, and touching your finger to your nose with your eyes closed – all designed to test your balance and coordination and establish whether you have been caught driving high.

It has become far easier for police officers to test drivers suspected of driving after cannabis use with the introduction of roadside mouth swab tests. These handheld kits can test the presence of certain drugs, including cannabis, in a matter of minutes. If drugs are found to be present in your system then you’ll be arrested and a blood or urine test will be taken at the police station. If this test also proves to be positive then a charge will be expected to follow.

What are the penalties I could face for driving after smoking weed in the UK?

The penalties for smoking weed and driving high in the UK are much more severe than they used to be. If you’re convicted of drug driving for any drug, including cannabis, you could face:

  • a minimum 12 month driving ban
  • an unlimited fine
  • up to 6 months in prison
  • a criminal record
  • an endorsement on your licence for a period of 11 years

A conviction after being caught driving following cannabis use can also cause additional difficulties for you including:

  • a big hike in your car insurance premiums
  • your employer will see your conviction on your licence (should you be required to drive for your living)
  • difficulties when travelling to certain countries such as the USA

Because there are no sentencing guidelines for drug driving setting out penalties for specific drug readings, the level of punishment for smoking weed and driving can be variable. Whereas a driver two times over a drink drive limit might face a ban of two years (twice the minimum ban) it is less certain what the penalty for driving high might be.

Some courts have been known to use the drink driving guidelines as a template of what sentence to impose, so if you are two times the drug-drive limit for cannabis then you could be facing a two-year ban, but this is not a given.

What is the penalty for causing death while driving when under the influence of cannabis?

Drivers who smoke weed and then cause a death while driving face significant punishment as the use of drugs are considered a significant aggravating factor. As in all instances of drug driving, there is no onus any more on the prosecution to prove that the drugs contributed to the level of impairment of the driver; just being over the legal limit for cannabis while driving is enough.

The penalty for causing death by careless driving while under the influence of cannabis is a prison sentence of up to 14 years, an unlimited fine, or both. The driver also faces a mandatory disqualification for a period of at least two years, and must complete a compulsory extended retest should they wish to drive again.

Is there any chance of paying a fine instead of being disqualified if I am found guilty of driving after smoking weed?

There’s absolutely no chance of paying your way out of this one by way of just a fine if convicted of any form of drug driving, including cannabis use. You will face an automatic disqualification of at least 12 months regardless of whether you have pleaded guilty or being found guilty after a trial.

In some circumstances, it is possible to present mitigation of special reasons to the court in order to reduce the length of disqualification. If accepted by the Magistrates then it may be possible to receive a period less than the mandatory 12 months or penalty points instead. In addition to the driving disqualification, you could face a fine for driving high, usually in the region of one-and-a-half weeks’ net wages.

I regularly smoke weed and have built up a high tolerance. In my view, my driving is in no way impaired, so can I still be found guilty of drug driving?

Sentencing in cases of drug driving, including cannabis use, do not take into account your level of tolerance, nor do they take into account the quality of your driving or the level at which your driving would be impaired by the drug. It’s a simple case of, if you are over the prescribed limit, then you will be prosecuted.

People who smoke weed and then drive often think that their driving would not be impaired, especially if they are regular users of cannabis. But the use of cannabis can slow a driver’s reaction and decision times and can also distort perceptions of time and distance, resulting in decreased control of a vehicle.

How long should I wait after smoking cannabis to safely drive within the legal limit?

This is far from a straightforward one to answer as the length of time that cannabis remains in the blood varies from person to person. The law states that it is an offence to smoke cannabis and drive whilst the active constituent of cannabis (delta-9-tetrahydrocannibinol) is above the prescribed limit of 2 µg per 1 litre of blood, but the length of time it would take to fall below this level is not uniform.

Opinions vary on how long a person who smokes weed would be legally safe (i.e below the 2 µg limit) to drive. Some argue that a driver would be safe after around 2 hours, while some suggest that you would only be safe to drive 24 hours after you last smoked a joint.

Ultimately, it is up to the individual cannabis smoker to decide when they may be safe to drive. The zero tolerance policy means that even though you may feel safe to drive there is no guarantee that you will be under the set limit. For this reason, the only sensible guidance we can provide is simply not to mix cannabis and driving, and in the worse case scenario to leave it at least 24 hours from your last joint before getting behind the wheel of a car.

I use cannabis for medical purposes. Can I use this as a defence against a cannabis-related driving charge?

In very rare cases can a cannabis-related driving charge be defended on medical use grounds.
Cannabis can be prescribed in an extremely limited number of cases in the UK for use by people with Multiple Sclerosis (MS) in the form of a mouth spray called Sativex.

The Department of Transport has provided guidance for Sativex users stating that MS sufferers, who in the opinion of a doctor are able to drive safely, should not be deterred from taking their medicine or from driving. In these circumstances there is a medical defence that can be raised should a person taking Sativex be pulled by police and fail a roadside screening test. Police carrying out a mouth swab test would in no way be able to distinguish between a driver taking cannabis and a driver taking Sativex, and for this reason a patient being treated with Sativex would be likely to give a positive result.

Drivers with MS should previously have notified the DVLA of their condition, and once they have been certified as safe to drive, they will be issued with a short-term driving licence (issued for up to 3 years) along with a letter showing advice concerning the medical defence. It is this documentation that they should present at the earliest opportunity in order that police can satisfy themselves that the medication is being taken under the supervision of a healthcare professional, and ensure their driving is not impaired, in order to allow them to proceed.

Cannabis use which is self-prescribed by people to help them with ailments such as arthritis or pain management would in no way be considered a valid medical defence against a charge of driving after smoking cannabis.

I have a previous drug driving offence within the last 10 years and have been charged with driving after smoking cannabis. Will I receive an automatic 3 year ban?

If you are a repeat offender then a mandatory minimum penalty of 36-month disqualification will apply. Section 34 of the Road Traffic Offenders Act confirms that if you have been convicted of a previous drug driving (or drink driving) offence in the last 10 years then a subsequent similar offence would trigger the automatic 3-year ban.

I’ve been caught ‘bang to rights’ driving after using cannabis. Is there any hope for me to avoid a ban?
Procedures for obtaining and analysing samples of blood for drugs have to be followed correctly and there are occasions where those undertaking these tests fall short of these standards. This means that with the right representation it is sometimes possible to get a charge dismissed.

How can Caddick Davies help you?

The new drug driving laws mean that a zero tolerance approach to cannabis use and driving when high is now largely in place, but this does not mean that there is no hope should you feel you are being unfairly criminalised for using a prescribed medication. Using our specialist knowledge we’ve secured hundreds of acquittals for the offence of “drug-driving” in recent years, so, give Caddick Davies a call see what we can do for you.

Contact us for a free initial consultation

All calls or enquiries to us are free and without obligation. When you get in touch with us will ask for all the details of your drug driving case and will then try to ascertain if there are any other issues which may be of relevance. Once we have done this, we will provisionally advise you and will propose a strategy as to how to approach your case in order to achieve the best possible outcome.

Our drug driving legal experts can provide a personalised approach to best fit the legal needs of each and every client we work with. When you are represented by a drug-driving solicitor from Caddick Davies, you’ll receive the best representation at all times. From the initial consultation through to the final outcome, your drug driving solicitor will keep you fully informed on the progress of your case.

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