The UK’s drink-driving limit was originally set in 1967, when there were a lot less cars on the road and our attitudes towards road safety in general were a touch more liberal than they are nowadays, to put it mildly.

So is it right almost half a century later – and with millions more cars on our roads – that we should still be allowed to drive so long as we are under the 80mg per 100ml blood/alcohol limit?

Those in the “yes” camp will argue that they are still perfectly capable of driving with such a piffling amount of alcohol in their system. And unless the law is changed, it is perfectly acceptable to drive with two pints of beer or three small glasses of wine on board, correct?

Not necessarily, because defining exactly how much you can drink before being over the 80mg limit is far from an exact science. What’s more, the level of alcohol contained in the average pint of beer or glass of wine has increased significantly since the limit was introduced 47 years ago.

A woman of six stone who hasn’t eaten much that day, and who is in emotional turmoil because her partner walked out on her the previous evening, is MUCH more likely to be “over the top” after drinking three glasses of wine compared with a big lad, who’s eaten a big lunch, and who’s in a great mood because he just got promoted at work. And yet technically, according to the guidelines, they should both be OK after three small glasses of wine.

Mood, size, recent diet, hydration and rates of metabolism are all key factors when it comes to working out precisely how much you can and can’t drink before driving, and in each instance the limit varies quite dramatically according to the individual.

So surely it’s time to bring the limit down in the UK so that’s it’s in line with the rest of Europe, if only to encourage people to not drink much at all if they are driving, rather than trying to drink to just beneath a legal limit, which might well be dubious anyway if you are small, anorexic and female?

There’s also one other oddity to consider with drink driving that’s about to come into force later this year, which you may or may not be aware of. In Scotland they are about to lower the limit to 50mg to fall in line with the vast majority of mainland Europe.

So, as from around October this year you could be driving up the A1 south of Berwick Upon Tweed having had a pie and a pint in a roadside pub, legally. But the moment you cross the boarder you will almost certainly be over the limit.

This alone is surely one good reason to bring our limit down to 50mg, and never mind the fact that our drink-drive limit is now chronically out of date.