DIY tests surprise drinkers

Pub-goers in Auckland were stunned to discover they were legally able to get behind the wheel, despite drinking as many as four glasses of wine.

After-work drinkers breath-tested by the Herald on Sunday said the results could encourage them to drive home - even if they didn't feel sober.

One man was "pretty shocked" to hear he was only just over the limit after drinking five pints.

And all nine of those tested guessed their blood alcohol level to be higher than their actual reading.

The legal limit for a person aged 20 or over is 400 micrograms of alcohol per litre of breath. For a person under 20, the legal limit drops to 150mcg.

Erica Hansen, a 28-year-old audiologist and self-described "lightweight", blew 390mcg after three wines.

She said: "I can't believe that. I don't feel like I could drive right now, but it's pretty scary thinking that I might actually be able to get in my car and drive home."

Matt, 32, a salesman from Auckland, registered 410mcg after drinking five beers and not eating any food.

He said: "I'd only ever drive if I had to after a couple ... I thought it would be higher for me, around the 600mcg mark."

Alan Burton, 62, and his wife Susan, 61, had both drunk half a pint before the test and guessed their levels would be around 300mcg.

The retired couple from Britain were amazed to find their levels differed greatly - Alan was barely a blip on the radar at 20mcg, while Susan blew 140mcg.

"I'm really shocked by the difference," said Susan.

"Back home I would only drive after drinking a small wine of about 125ml, but it's interesting we have no idea about the limits here."

Auckland City road policing manager Inspector Gavin McDonald said even though people estimated their blood alcohol levels to be higher, some would still get behind the wheel after a couple of drinks.

Even if you managed to pass a test after two drinks one night, you may not be able to drink the same amount the following day and pass.

"Basically, if you are going to have a drink, don't drive at all," says McDonald. "[The levels] can depend on your metabolism, how much you've had to eat, and fatigue.

"Reactions will be much slower even if you are actually under the limit."

The AA warned against drinkers breathalysing themselves with DIY kits.

AA Motoring affairs general manager Mike Noon said: "We do not support people checking their blood alcohol level in a pub to see if they are okay to drive.

"Twenty minutes later they could be over the limit."

The AA recommends drivers should only consume one or two drinks before driving.

New Zealand Transport Agency figures show alcohol or drugs were a contributing factor in 33 per cent of all road deaths in 2008. The year before, alcohol or drugs were a contributing factor in 117 fatal road crashes, resulting in 128 deaths.

The pub-goers were tested using a SC3000 digital breathalyser kit, supplied by SoberCheck NZ.