Drink & Drug Driving
Roadside testing, station procedure, the England & Wales and Scotland legal limits, the s.5A specified-drug-limit offence and the s.7(6) failure-to-provide offence — an officer quick-reference cited to the Road Traffic Act 1988.
Unofficial independent resource — always verify with official sources (College of Policing, your force, PFEW).
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What are the drink and drug driving procedures and legal limits for officers in England & Wales?
A positive or refused roadside screening breath test (required under s.6 RTA 1988) leads to arrest and an evidential breath test at custody, using two specimens of breath with the lower reading taken as evidence. The prescribed limits in England & Wales are 35µg per 100ml of breath, 80mg per 100ml of blood, and 107mg per 100ml of urine; Scotland's limits are lower, at 22µg breath, 50mg blood and 67mg urine.
Driving with a specified controlled drug above its prescribed limit is a separate offence under s.5A RTA 1988, covering 17 controlled drugs and supported by Field Impairment Tests and roadside oral fluid screening. Failing to provide a specimen of breath, blood or urine without reasonable excuse is itself an offence under s.7(6) RTA 1988, carrying the same penalties as the substantive drink driving offence.
A reference to roadside and station drink/drug-driving procedure, the prescribed alcohol limits, the specified controlled-drug offence and the failure-to-provide offence under the Road Traffic Act 1988. It is educational reference, not tactical guidance — follow your force policy, training and current law.
Roadside breath test
A screening breath test device is used at the roadside to establish whether a driver is over the prescribed limit. If the result is positive or the driver refuses, the officer should arrest.
Officer powers under s.6 Road Traffic Act 1988 allow you to require a test at the scene of a road traffic collision (RTC) or if you reasonably suspect drink or drug driving.
The test can be required of any person driving, attempting to drive, or in charge of a motor vehicle on a road or public place.
Station procedure
At custody, an evidential breath test is conducted using an approved device (e.g., Intoximeter). Two specimens of breath are taken and the lower reading is used as evidence (s.8(1) RTA 1988).
The former "statutory option" — under which a driver whose lower breath reading was 40–50µg could require it to be replaced by a blood or urine specimen — was abolished on 10 April 2015 (the Deregulation Act 2015 repealed s.8(2) RTA 1988). Whether a blood or urine specimen is taken is now a decision for the constable under s.7(3) RTA 1988 (for example where no reliable breath device is available, or for medical reasons).
The station procedure must commence within a reasonable time of arrest. Delays can be challenged by the defence, so act promptly and record all timings.
Legal limits
England & Wales limits:
| Specimen | Limit |
|---|---|
| Breath | 35µg per 100ml |
| Blood | 80mg per 100ml |
| Urine | 107mg per 100ml |
Scotland has lower limits: 22µg breath, 50mg blood, 67mg urine. Be aware of the jurisdiction if operating near the border.
Drug driving (s.5A RTA 1988)
The offence of driving with a specified controlled drug above the prescribed limit covers 17 controlled drugs, including cannabis, cocaine, and certain prescription medications.
Field Impairment Test (FIT): a series of tests including pupil examination, walk-and-turn, one-leg stand, and finger-to-nose. Used to assess impairment at the roadside.
A Drugalyser (roadside oral fluid screening device) can detect cannabis and cocaine. A positive result or refusal supports arrest.
A blood sample is required for prosecution — this must be taken by a healthcare professional (HCP) at custody.
Failure to provide (s.7(6) RTA 1988)
It is an offence to fail to provide a specimen of breath, blood, or urine without reasonable excuse. This carries the same penalties as the substantive drink driving offence.
“Reasonable excuse” is narrowly interpreted — typically a genuine medical condition that physically prevents the suspect from providing a specimen.
You must clearly warn the suspect that failure to provide may render them liable to prosecution. Record the warning and the suspect’s response verbatim in your pocket notebook.
Officer tips
- Always note the time of the suspect’s last drink (their account) and record it.
- Record observable behaviour: slurred speech, unsteady on feet, smell of intoxicants, glazed eyes, poor coordination.
- If the suspect elects to provide blood instead of breath (where applicable), arrange for an HCP to attend custody promptly.
- Keep the custody record updated with all timings, decisions, and the suspect’s demeanour throughout the process.
- Ensure body-worn video is activated — it captures behaviour evidence that supports the prosecution case.
Related reading
Primary sources
BlueLineHub is independent and unofficial. Always verify with the authoritative source below.
- Verify on official source
Road Traffic Act 1988, section 6 — preliminary tests
The power to require a preliminary breath test at the roadside or the scene of a road traffic collision.
Last checked: August 2026 - Verify on official source
Road Traffic Act 1988, section 5A — driving with a specified controlled drug above the specified limit
The drug-driving offence covering the specified controlled drugs and their prescribed limits.
Last checked: August 2026 - Verify on official source
Road Traffic Act 1988, section 7 — provision of specimens for analysis
Provision of specimens for analysis; s.7(6) creates the offence of failing to provide a specimen without reasonable excuse.
Last checked: August 2026 - Verify on official source
Road Traffic Act 1988, section 8 — breath specimen showing higher alcohol level to be disregarded
Requires the lower of the two breath specimens to be used and the higher disregarded (s.8(1)). The former s.8(2) blood/urine "statutory option" was repealed on 10 April 2015 by the Deregulation Act 2015.
Last checked: August 2026 - Verify on official source
Road Traffic Act 1988, section 5 — driving or being in charge with excess alcohol
The offence of driving, attempting to drive, or being in charge of a vehicle with alcohol over the prescribed limit.
Last checked: August 2026 - Verify on official source
Road Traffic Act 1988, section 11 — interpretation (the prescribed limit)
Defines the prescribed limit: 35µg/100ml breath, 80mg/100ml blood, 107mg/100ml urine in England & Wales (Scotland's limits are lower).
Last checked: August 2026
Frequently asked
- What are the prescribed alcohol limits in England & Wales?
- 35µg per 100ml of breath, 80mg per 100ml of blood, and 107mg per 100ml of urine. Scotland has lower limits: 22µg breath, 50mg blood, 67mg urine.
- Can a driver demand a blood test instead of the breath reading?
- No — not since 10 April 2015. The former "statutory option" (which let a driver whose lower breath reading was 40–50µg require a blood or urine specimen instead) was abolished when the Deregulation Act 2015 repealed s.8(2) RTA 1988. Whether blood or urine is taken is now the constable's decision under s.7(3) RTA 1988.
- Is it an offence to refuse to provide a specimen?
- Yes. It is an offence under s.7(6) RTA 1988 to fail to provide a specimen of breath, blood, or urine without reasonable excuse, carrying the same penalties as the substantive drink driving offence.