It is an image that has confused motorists and perplexed physicists since the rubber first met the road; how did the driver in a common roadside sign manage such a bizarre skid mark?

Upon closer inspection, the driver has managed to cross the tyre tracks of both front and rear tyre — but only on one side — while also managing to oversteer the car to the point it begins to lift.

Bizarre? Yes, but that is the aim of such roadside warning signs says a motoring expert.

"Technically, it's nigh on impossible for a driver to get themselves into the situation depicted in this image," said Professor Maxwell Cameron from Monash University's Accident Research Centre.

"Or if it was, the driver would be in a lot of trouble, perhaps they've even spun around and it's only the one wheel doing all the damage.

"But this is the aim of this particular sign. It's supposed convey the idea the road is such that you may skid and lose control and to reinforce that they show what is clearly an impossible situation."

Tested on target audiences

Professor Cameron said before road signs were deployed, they are tested on "target audiences" to ensure the correct message was conveyed.

"People just don't stick them out there willy-nilly," Professor Cameron said.

"They're put before a committee that reviews all signs to ensure they meet standards and in a case like this sign, all states met to agree on the design.

"It doesn't necessarily mean it's a sensible sign, it just means it works."

As for the colour of signs, Professor Cameron also said different colours were used for different situations.

"Yellow and black are generally advisory signs while red signs, stop and give way for example are reserved for more of a mandatory requirement," he said.

"Again, it's something you'll find uniform across most of the world."

As driver and vehicle behaviour changed, Professor Cameron said he could also foresee the need for updated signage, although trying to convey another way of approaching danger would be difficult.

"Perhaps once the autonomous car becomes common place we may need to revisit what we currently see out on the roads," Professor Cameron said.

"But the image of the sliding car has been around for as long as I can remember.

"It appears to do the trick so I can't see it disappearing anytime soon."