As the law stands, drivers are perfectly entitled to get behind the wheel with anything up to 80mg/100ml of alcohol in their blood. At 81mg/100ml, though, they face arrest, a court appearance, a fine and a lengthy ban from driving. The knock-on effects of this often devastate their livelihoods and private life.
However, if the legal limit is lowered to effectively zero, there could be a case to instigate a tiered punishment system, the same as there is with virtually every other crime.
Take speeding, for example. If you're caught doing 45mph in a 40mph limit, you'll be fined 60 and given three points on your licence. If you're doing 90mph in a 40mph zone, you'll probably be banned. Should the same logic be applied to drink-driving?
The Parliamentary Advisory Council for Transport Safety (PACTS) believes a tiered punishment system could work.
'If a 20mg limit was introduced, it would be feasible to have a system where any driver caught between 20mg/100ml and 50mg/100ml would get six points on their licence, which would stay there for 10 years,' says executive director Robert Gifford. 'That way, two smaller drink-drive offences in a 10-year period would result in a ban, and drivers over 50mg would be disqualified straight away.'
The AA believes that any driver caught above 50mg/100ml should be banned from driving, but admits disqualification might be too harsh if the limit was lowered to 20mg/100ml. However, Brake takes the hard line, and says any driver caught over 20mg should face a mandatory ban.