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Guide to Drug Driving – Knowing the Facts [INFOGRAPHIC]

Some choose to drive a vehicle when under the influence of drugs even though it is illegal to do some.  Many of these same people would not consider driving whilst under the influence of alcohol, but feel it is permissible to drive a vehicle whilst under the influence of drugs such as marijuana or prescription medications.

If you are unfit to drive a vehicle because you are taking either legal or illegal drugs, it’s simply illegal and immoral to do so.

If you are taking prescription medications and you are unsure if you should drive whilst using these drugs, we urge you to speak to your local doctor as soon as possible.

If you are stopped by police, there is a high chance you will be asked to complete a field impairment assessment if it is suspected you are under the influence of drugs, legal or otherwise.

This ‘field impairment assessment’ is comprised of a number of tests. For instance, you will be asked to walk in a straight line.  You may also be asked to take a drug test. These tests are able to detect drugs such as cocaine and marijuana.

If you fail these tests, then you will be arrested and taken to the police station. Here, you will be asked to take both a urine and blood test.

If these tests conclusively prove you have driven a vehicle whilst under the influence of drugs, you will be charged. You will then have to attend a criminal court. If it’s your first offence of this nature, it’s likely you will be fined.

From 2nd March 2015, the law on drug driving changed with the Crime and Courts Act. The old offence of driving whilst unfit through drugs under the Misuse of Drugs Act 1971 remains in place but is now rarely used as the old offence requires there to be proof of driver impairment.

Before 2015, prosecutors would need to prove ‘driving impairment’. This offence was known as ‘driving whilst unfit through drugs’. The law was altered because the burden of driving impairment was problematic for prosecutors.

Now, you will be guilty of an offence if a drug test proves you have consumed more than a certain quantity of drugs. It is thus no longer necessary for persecutors to prove ‘driving impairment’. Since the law was changed in 2015, the number of people prosecuted for drink driving in the UK has surged.

Below, we list the ‘drug drive’ limit for a variety of different illegal drugs:

Illegal drug Threshold limit in blood
Benzoylecgonine 50µg/L
Cocaine 10µg/L
Cannabis 2µg/L
Ketamine 20µg/L
LSD 1µg/L
Crystal Meth 10µg/L
MDMA 10µg/L
Heroin 5µg/L

Below, we list the ‘drug drive’ limit for a variety of different prescription drugs:

Prescription drug Threshold limit in blood
Amphetamine 250µg
Clonazepam 50µg/L
Diazepam 550µg/L
Flunitrazepam 300µg/L
Lorazepam 100µg/L
Methadone 500µg/L
Morphine 80µg/L
Temazepam 1,000µg/L

What if you are taking legally prescribed drugs?

It is illegal to drive a vehicle if you are taking drugs that impair your ability to drive.  This equally applies to ‘over-the-counter’ drugs that are not prescribed by your doctor.

Examples of prescription drugs that are known to impair your ability to drive a vehicle include:

  • Oxazepam
  • Clonazepam
  • Temazepam
  • Lorazepam
  • Methadone
  • Diazepam
  • Amphetamine
  • Flunitrazepam
  • Morphine and other opiate drugs

If you are using these drugs within the guidelines, you will not commit an offence merely by driving and having these drugs in your system.

However, if a drug test reveals you are using a greater quantity of these drugs than the limit listed above, you may be subject to criminal prosecution.

Penalties for drug driving in the UK

If you are convicted for drug drive offence, you could be liable to;

  • Minimum 1-year driving ban
  • Unlimited fine
  • Up to 6 months in prison
  • A criminal record

The fact you were prosecuted for a drug-driving offence will be recorded on your driving licence for an 11-year period. This will typically increase your insurance costs during this period.

If you cause death by dangerous driving whilst under the influence of drugs, you could receive a prison sentence of up to 14 years.

Drug driving laws in the USA

Drug driving laws are set by each state. For a list of drug driving laws in your state, click here.

The US National Highway Traffic Safety Administration’s Drug Evaluation and Classification program (DEC) defines a drug as ‘any substance that, when taken into the human body, can impair the ability of the person to operate a vehicle safely’.

Law enforcement test for drugs by carrying out urine, blood and breath tests.

The DEC programme recognises seven separate categories of impairing drugs:

  1. CNS depressants – Drugs such as alcohol, barbiturates, and benzodiazepines fit in this category
  2. CNS stimulants – Drugs such as cocaine and amphetamines fit in this category
  3. Hallucinogens – Drugs such as LSD, peyote, and MDMA fit in this category
  4. Dissociative anaesthetics – drugs such as PCP and Ketamine fit in this category
  5. Narcotic analgesics– synthetic and derivative opiates fit in this category
  6. Inhalants – volatile solvents, anaesthetic gases and aerosol sprays fit in this category
  7. Cannabis – marijuana fits in this category

Drug driving infographic

Below, we share an infographic about driving whilst under the influence of drugs. Please share this infographic on your own website.

Please use the ‘infographic embed’ code we provide at the footer of this post: