If you happen to be caught out and have a reading below the old level, but above the new level, you will not get a criminal conviction. However, you will be fined $200 and receive 50 demerit points.
There is a lot of discussion going on about what that means regarding how much you can actually have to drink and still not be over the limit.
There are many factors which will determine how quickly alcohol is absorbed into your system, including whether you are male or female, how much you weigh, and how much you have eaten before drinking.
The Institute of Environmental Science and Research (ESR) believes most adults may be able to drink two standard drinks over two hours and are likely to remain under the new drink-driving limits for adults.
But just be careful you know what a standard drink is - the way you pour a glass of wine at home may be two or more standard drinks. A standard drink is equivalent to 330ml of beer, 100ml of wine or 32ml of spirits, containing 4, 13 and 40 per cent alcohol respectively.
But let's have a look at why the Government is making this change.
It is estimated the lower limit will save, on average, 3.4 lives and prevent about 64 injuries per year, with a reduction in social costs of about $200 million over 10 years.
The 2011 introduction of a zero alcohol limit for drivers under 20 has significantly reduced the number of drink-driving offences. We expect the new adult limit to do the same.
And this will also bring New Zealand into line with many other countries, including Australia.
The number of drivers being caught over the limit has been steadily reducing for years.
We've seen a change of attitude to drink driving over a generation. What people of our parents' generation thought was fine will be unacceptable to most people now.
Of course there will always be those who will take the risk, and those who will repeatedly do so. The good news is international evidence clearly shows that lowering the drink-driving limits leads to reduced drink-driving offending at all alcohol levels, including those in the high range.
The lower limits will take some getting used to. At times they may be inconvenient and expensive if you have to catch a cab, but they are being put in place with some very good science behind them that show they will reduce the harm done on our roads.
So as you party up over the holidays, just make sure you know the new limits, make plans to get home safely, and make sure that your friends and family do the same.
-Todd McClay is the National Party MP for Rotorua.
