Road Traffic - Drink and Drug Driving
Plain-English digest of CPS prosecution guidance.
AI-generated summary — not verbatim. This is a plain-English digest, not the official CPS text. It may omit detail or fall out of date. Do not rely on it for a charging decision — read the full guidance on cps.gov.uk and check the current legislation.
This CPS prosecution guidance addresses road traffic offences related to drink and drug driving, outlining evidential considerations, various sections of the Road Traffic Act 1988, and procedures for handling these cases. It includes detailed descriptions of offences such as driving under the influence, the provision of samples, and challenges surrounding evidential testing, alongside public interest factors for prosecution. The guidance also specifies the procedures for dealing with minors and the collection of post-driving consumption evidence.
Key points
- Clear public interest in prosecuting drink or drug driving offences.
- Prosecutors should apply the Full Code Test for charging decisions.
- Charges under sections 4 and 5 may overlap in cases of impairment.
- Medical defences should be disproven beyond reasonable doubt in drug cases.
- Preliminary tests are important for determining impairment.
- Existing guidelines must be followed for the proper processing of samples.
Public-interest factors
- Deterring drink and drug driving to enhance public safety.
- Ensuring that offenders are brought to justice to protect road users.
- Reinforcing the message that drinking or using drugs and driving is unacceptable.
- Promoting community confidence in road safety enforcement.
This is a factual digest of guidance published by the Crown Prosecution Service. Digested 2026-07-15. BlueLineHub is independent and not affiliated with the CPS.