Illegal drugs and driving in Scotland

Last updated: 21 October 2019

The law

You can commit 2 different crimes if you take drugs and drive.

It's a crime to drive if you're:

  1. over the limits for certain drugs
  2. unfit because you've taken any drug

You can be convicted of either crime.

The law also applies to prescription and over the counter drugs.

The police can do a roadside drugs test if they suspect drug driving.

1. Driving over the limits for illegal drugs

It's a crime to drive if you're over the limits for certain drugs.

The illegal drugs the law applies to are:

  • cannabis (delta-9-tetrahydrocannabinol)
  • cocaine and benzoylecgonine (a chemical produced when cocaine is broken down by your body)
  • heroin (6-monoacetylmorphine)
  • ketamine
  • LSD (lysergic acid diethylamide)
  • MDMA or ecstasy (methylenedioxymethamphetamine)
  • meth (methylamphetamine)
  • speed (amphetamine)
The limits for these illegal drugs are close to zero (except amphetamine). This means the limits are so low you're likely to test positive if you take any amount.

Amphetamine has a different limit to balance its use as a prescription drug against its abuse.

Find out the limits for illegal and prescription drugs

What the limits mean for you

The limits are what's measured in your blood and not how much you can take.

Some drugs can stay in your blood for several days after you take them.

Many factors affect this including:

  • age
  • weight
  • how hydrated you are
  • how your body tolerates the drug

It's impossible to say what dose of any drug will put you over the limits or how safe it is to drive after taking it.

But you're likely to test positive if you take even a small amount of illegal drugs or drugs not prescribed for you.

2. Unfit to drive through drugs

It's a crime to drive if you're unfit because you've taken any drug.

For example if it makes you drowsy or affects your judgement or concentration.

This applies to any drug and includes:

  • illegal drugs (for example cocaine or cannabis)
  • prescription drugs (for example tramadol, diazepam or medicinal cannabis)
  • over the counter medicines (for example co-codamol or antihistamines)

It's up to you to be sure you're fit to drive. Illegal drugs do not improve your driving.

You can still be convicted of this crime even if you're not over drug limits.

Roadside drugs test

The police can stop you if they think you're drug driving.

They can:

  • test you at the roadside for illegal drugs using saliva from a mouth swab

  • make you do a field impairment test – including checking your pupils and asking you to walk in a straight line

The police will arrest you if you fail either test.

They will then take you to a police station for blood tests.

At this point you could be charged with a crime.

You could be convicted if it's proven you were unfit to drive or the blood tests show you've taken drugs.

What happens if you're convicted

If you're convicted of drug driving you'll get:

  • a minimum 1 year driving ban
  • between 3 and 11 penalty points
  • a fine of up to £5,000 and/or up to 6 months in prison
  • a criminal record

Your driving licence will show you've been convicted of drug driving. This will last for 11 years.

You could go to prison for up to 14 years if you cause death by dangerous driving while unfit through drugs.

Other problems you could face

A drug driving conviction can also affect:

  • car insurance costs
  • current or future jobs
  • travelling to countries such as the USA
  • volunteering – especially with children or people who have support needs

Report drug driving

Find out how to report a crime in Scotland.