A medical centre's efforts to curb Christmas party drinking may have the opposite effect, say police.
Primecare Medical Centre in Whangarei is hiring out a breath-testing machine so people can see if they are sober enough to drive.
Spokeswoman Christine Sapwell said some companies had already hired the machine. Others had booked
it for the coming weeks.
But Inspector John Kelly, acting national road policing manager, is concerned about the scheme.
Police knew of cases where people had used breath-testing machines at parties for drinking games - competing for the highest reading or to get closest to the legal limit, he said.
"I don't want to knock this, but we have our reservations."
Land Transport Safety Authority spokesman Andy Knackstedt said people could be highly intoxicated yet still be below the legal limit.
Reaction times suffered after just one drink, and people should not confuse being legal with being safe.
"Really the best thing to do isif you are planning on drinking, don't plan on driving.
"I would like to think that most people would have enough common sense and decency not to drive if they are feeling impaired."
Mr Kelly also questioned how accurate the machines were.
But Ms Sapwell said her understanding was that the machines were just as accurate as the ones the police used.
She said the idea came to her after she used one of the devices at a health and safety conference in Wellington in September.
The medical centre charges a flat rate of $55 and 10c for every breath test.
The whole point of it, Ms Sapwell said, was to raise awareness about alcohol and to show people how the reading of the breath-testing machine did not necessarily reflect whether they were in a fit state to drive.
"You think you have had a couple of wines and will be fine to drive because you should be under the limit.
"What we wanted to do was to say you might be under the limit but you are still not safe to drive."
