November 14, 2015 10:00am by David Farrar

Robertson on drink driving limits

Hospitality CEO Bruce Robertson writes:

They can be funny things, laws.

We may not always agree with all of them, but a civilised society requires clear laws to function.

Those laws should be fair and reasonable, reflect the views of citizens, and be easy to understand and obey.

This is not the case with the lower drink-drive limit, brought into effect in December last year.

It’s not the law that Hospitality New Zealand takes issue with. The real issue is that police and NZTA are purposely ignoring that the law means you can have a few drinks and drive.

Worse still, they are using scare tactics to promote public ignorance of how to stay within the law.

The role of police is not to make moral judgments. Their role is to enforce the laws put in place by Parliament and catch those who break them.

So let’s be absolutely clear – it is perfectly legal for an adult to have a drink and then drive.

The law is explicit about this. It’s also explicit that there are limits. But what do limits practically mean if no one understands them?

What’s the point when those legal limits are deliberately ignored and misinterpreted by the authorities?

That’s the nub of it – the police and NZTA should not be promoting their “interpretation” of the law. Their job is to make it clear how the law applies.

The police and the NZTA decided we couldn’t handle the law or the truth. Their campaigns do not “inform” us about the limit.

They say you should not drink anything because even a few drinks will push you over the limit. This is not true.

The key point is that we should know what the legal limit is, so we can make sure we don’t break the law.

Of course one should also exercise judgement about safeness to drive regardless of the law. But we do that anyway. If one feels tried, or thinks one may be overly affected by alcohol, you often get someone else to drive.

Our “rule of thumb” shows men can have three standard drinks over two hours and women two standard drinks over two hours.

By following this simple, easy-to-understand guide, the vast majority of adults will be easily under the lower limit.

That means you safely have a couple of after-work beers with mates, or a couple of glasses of wine with dinner – just as the law intends (and despite what the police and NZTA would have you believe).

It’s important to note, too, that we didn’t simply pull these figures out of a hat.

The rule of thumb is based on analysis by the Institute of Environmental Science and Research (ESR), which fully supports it.

What’s more, our rule of thumb is even more conservative than ESR’s own recommendations. Three drinks will have most men easily within the limit.

It is conservative. A BAC calculator shows the following estimates for standard drinks to remain below 0.05 over two hours:

Male 80 kgs – 4.2
Male 70 kgs – 3.9
Male 90 kgs – 4.5
Female 60 kgs – 3.1
Female 70 kgs – 3.4
Female 80 kgs – 3.7

So the guidelines of 3 for men and 2 for women is pretty conservative.

Even a 30 kg woman will only get a BAC of 0.03 with two standard drinks over two hours. And unless a male weighs under 45 kgs, three standard drinks will have them under 0.05. Of course there is some variation beyond weight and gender but the guideline of three and two for men and women looks very sensible.

Now you may argue that any alcohol is too much, and there is increased risk at below 0.05. Well here’s the official data on BAC levels in fatally injured drivers.

BAC of 31 to 50