If you have been stopped by police while driving with a medical cannabis prescription, this guide explains what may happen next, what roadside tests can and cannot prove, and how to respond calmly and lawfully. 

It is designed for medical cannabis patients and all motorists across the UK who need clear information about police stops, saliva testing, impairment assessments, arrest, custody and evidential blood samples.

The Roadside Survival Guide also explains the difference between having THC in your body and being impaired, when the medical defence may apply in Great Britain, what evidence you should keep, and what steps to take if you believe something went wrong. It is a practical public information resource and does not replace legal or medical advice.