The offence
Section 5 of the Road Traffic Act 1988 makes it an offence to drive or attempt to drive with alcohol above the prescribed limit. The limits are 35 micrograms of alcohol per 100 millilitres of breath, 80 milligrams per 100 millilitres of blood, or 107 milligrams per 100 millilitres of urine. Section 4 covers driving while unfit through drink or drugs. ‘Being in charge’ while over the limit is also an offence.
The procedure and defences
- Procedural compliance with the roadside breathalyser and the evidential machine
- The 'hip flask' defence — alcohol consumed after driving had stopped
- 'Rising curve' arguments — alcohol still absorbing at the time of the test
- Dispute over whether you were driving or 'in charge' of the vehicle
- Reliability of specimen handling and analysis
Penalties
Driving or attempting to drive over the limit carries a minimum disqualification of 12 months, extended to three years if you have a similar conviction in the previous ten years. The court can impose up to six months’ imprisonment and an unlimited fine, particularly where aggravating factors apply. For ‘being in charge’, disqualification is discretionary unless the court finds a special reason not to disqualify.
Frequently asked questions
35 micrograms per 100 millilitres of breath, 80 milligrams per 100 millilitres of blood, or 107 milligrams per 100 millilitres of urine.
A minimum 12-month disqualification applies to driving over the limit. The court can avoid disqualification only where it finds a ‘special reason’ — for example, driving a very short distance in a genuine emergency, or a drink being spiked without your knowledge.
A special reason is a factual circumstance that, while not a defence to the charge, allows the court not to disqualify. Examples include a very short distance driven in an emergency, or a drink spiked without your knowledge. It must be raised and argued in court.
Yes. Procedural compliance with the testing equipment, specimen handling and analysis can all be challenged. The ‘hip flask’ and ‘rising curve’ arguments are also available in the right circumstances.