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Draft: these answers come from research checked on 16 October 2026 and have not yet been reviewed by a solicitor. Each answer shows how it was checked. This is general information, not legal advice.

Driving

5 questions

  1. 44What's the drug-drive limit for weed?
  2. 45I smoked last night. Can I drive this morning?
  3. 46I have a prescription. Can I drive?
  4. 47What if I refuse a roadside drug test?
  5. 48How long does drug-driving stay on my licence?

44.“What's the drug-drive limit for weed?”

In England and Wales, 2 micrograms of THC per litre of blood — effectively "don't drive after using". Penalties: ban of at least 12 months, unlimited fine, up to 6 months' prison, criminal record.[41]

Law:
RTA s.5A; 2014 Specified Limits Regulations
Where:
England and Wales (SCO 2019 Regulations; NI no set limit)
Source:
legislation.gov.uk
Checked against the named source on 16 Oct 2026

45.“I smoked last night. Can I drive this morning?”

You could still be over the limit; THC can stay in blood for hours or longer. There is no safe waiting time we can give. If in doubt, don't drive.

Law:
RTA s.5A
Help:
FRANK
Where:
All of the UK
Checked against the named source on 16 Oct 2026

46.“I have a prescription. Can I drive?”

There is a medical defence to the over-the-limit offence if you took it exactly as prescribed. It doesn't apply if your driving is impaired.[22][42] Ask your prescriber and check DVLA rules for your condition.

Law:
RTA s.5A(3); s.4
Help:
prescriber; DVLA
Where:
E&W, SCO
Checked against the named source on 16 Oct 2026

47.“What if I refuse a roadside drug test?”

Refusing without reasonable excuse is an offence with similar penalties, and you lose the medical defence.

Law:
RTA ss.6–7
Help:
motoring solicitor
Where:
All of the UK
To be checked against the live source before final publication

48.“How long does drug-driving stay on my licence?”

11 years.

Law:
Road Traffic Offenders Act 1988 s.45
Help:
DVLA
Where:
Great Britain
To be checked against the live source before final publication

General information, not legal advice. For your situation: a solicitor (free at the police station), Release or Citizens Advice.

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