"Just remember that someone suffering from a head cold can have considerably slower reaction time than someone driving within current UK legal limits for blood alcohol"

You're probably right Geoff, but there's no evidence that a head cold increases the sufferer's propensity towards reckless and unlawful behaviour, whereas there's plenty of uncontestable evidence that alcohol does (Don't believe me? Take a walk around your local town-centre pubbing/clubbing area at midnight on Friday or Saturday night).

But I agree, the limit's probably OK as it stands - it's enforcement that's required, take the "I'm a better driver when I've had a few pints" nutcase-brigade off the road.