Daytime DUI busts on the increase

The number of drink drivers busted between 6am and midday is growing, as a new study shows most motorists don't know how long it takes alcohol to leave their system.

Here's a sobering thought as we head into the summer holidays.

Most drivers still don't know how long it takes for alcohol to leave their system, even though random breath testing has been around for more than 30 years.

Police figures show there is an increase in the number of people busted over the limit the morning after a big night out.

Two years ago, the number of drivers caught over 0.05 between 6am and midday represented 10.6 per cent of all DUI arrests.

Last year the number of drink drivers booked in the morning climbed to 11.6 per cent of all DUIs.

So far this year the number of drink drivers booked in the 6am to midday timeslot has risen again, to 12.2 per cent of all DUI offences.

The rise in the number of drink drivers booked during the day comes amid a 5 per cent drop in DUI arrests between 6pm and midnight -- and an even sharper drop of 8.5 per cent between midnight and 6am.

A lot of drivers underestimate the ongoing affect of alcohol

The figures from NSW Police were revealed as a study of 1022 motorists -- commissioned by the Australian Road Safety Foundation and funded by Bob Jane TMarts -- found 61 per cent of drivers don't know how long it takes for alcohol to clear their system.

Disturbingly, 22 per cent of respondents in the survey admitted to driving the next day even though they thought they might be over the limit.

"A healthy liver breaks down less than one standard drink per hour, so even if you've had four or five hours sleep before getting behind the wheel, you could still over the limit," said Russell White, CEO of the Australian Road Safety Foundation.

Mr White said a lot of drivers underestimate the ongoing affect of alcohol.

"There are so many variables. You're affected by the amount of alcohol you drink, over what period of time, and how long it takes your body to process it," said Mr White.

"Depending on how big a night you've had, alcohol can well and truly still be in your system well into the second day."

Mr White said "the Australian psyche" means many drivers use the 0.05 blood-alcohol limit as a target, "to get as close to limit as possible".

The best way is to impose a zero limit on yourself. If you drink at all, don't drive

"But it doesn't take much to go 0.05 and even at 0.05 there is still some impairment. That's why you can get busted for being right on 0.05."

He added that it is difficult for people to keep track of how much they've had to drink this time of year "because glasses keep getting topped up".

"People lose track of how many glasses they have," he said. "Two glasses of champagne for example is equivalent to three standard drinks. But a lot of people don't realise that. The best way is to impose a zero limit on yourself. If you drink at all, don't drive."

Erica, 26, from Brisbane, was busted for DUI the day after a big night out. She had drinks after work on a Friday night and then got up early the next day to watch her father play football.

But she was stopped for a random breath test not far from home in the morning and recorded a mid-range reading.

"I thought I might be a little bit over but not to that magnitude," said Erica, who asked that her surname not be used.

Erica has since completed a driver safety course as part of the Queensland Traffic Offenders Program. The three-week course teaches motorists the risks of driving drunk.

"I now know it can take up to 16 hours for an average size female to go back to zero after her last drink," said Erica. "If you feel hung over it means you're probably still over the limit. I'm super paranoid these days, I tell all my friends not to drive the next day, regardless of how you feel."

Do you think there should be more targeted education about driving the morning after drinking? Tell us about it in the comments below.