Facts. Marcus, 31, is pulled over. The car smells of cannabis. Officers find a small amount in the glovebox. He used cannabis the night before.
What the law says. Possession rules are as in Scenario 1, and police have search powers for vehicles (MDA s.23). Separately, it is an offence to drive with more than 2 micrograms of THC per litre of blood (Road Traffic Act 1988 s.5A) or while impaired by drugs (s.4).[27] Under s.5A, police do not have to prove impairment.[28]
| If… | Then… |
|---|---|
| Possession only, negative roadside drug test | Possession ladder (Scenario 1) |
| Positive roadside test | Arrest, blood sample; s.5A charge if over 2 µg/L |
| Impaired driving observed | s.4 investigation |
| Refuses a specimen without reasonable excuse | Separate offence, treated like drug driving [unverified — RTA s.7(6)] |
| Second drug or drink-drive conviction within 10 years | Minimum 36-month ban (Road Traffic Offenders Act 1988 s.34; secondary source Scarsdale Solicitors, 2026) |
Outcome. A s.5A conviction brings a mandatory minimum 12-month disqualification, an unlimited fine and up to 6 months' imprisonment.[29] It is a criminal conviction, and the road safety charity Brake states the licence endorsement "will last for 11 years" (secondary source). Insurance and driving jobs are often affected more than the fine.
Myth. "I felt fine the next morning, so I'm legal." The limit is a blood level, not a feeling. No "safe" waiting time can be given.
Rights. Ask for a solicitor before interview.