Many a state highway around New Zealand has a van tucked behind a corner with a speed camera, or police offer parked up waiting for people to tick over the speed limit.
Since the dawn of headlights there has been a tool Kiwi motorists have used to alert one another - the flash of your lights.
Seven Sharp asked a bunch of New Zealanders if they knew about the secret code, all but one passed the test, in Britain, apparently the flash is a signal your lights are off.
Caroline Perry from road safety charity Brake Aotearoa says while the manoeuvre is not technically an offence, according police, they do discourage drivers from flashing their lights to warn other drivers about upcoming speed cameras.
“If you are speeding, you are more likely to be involved in a crash, and it’s more likely that someone is seriously injured or killed in that crash as well.
“We want to ensure that drivers who are putting lives at risk on the road are being penalised,” she said.
She says a flash of the lights might deter people momentarily but they are likely to speed up again once they have passed the speed camera.
Perry says flashing may also serve as a distraction for other drivers.