Who knew strange animals born with a sack stuck to their bellies would prove to be the largest hurdle in the advent of driverless vehicles? In areas where you'll find marsupials, anyway.

While North American drivers have long grown used to smacking deer with their personal vehicles, it's a different story in the land of Paul Hogan, Nicole Kidman, and the amiable fellow from Jurassic Park. A full 80 percent of vehicle-animal collisions on that extremely large island and/or continent involve a kangaroo. It now seems the manner in which the limber creatures get around has created a headache for a certain Scandinavian car company - one hoping to lead the industry in hands-off driving.

Volvo has already flung XC90s outfitted with autonomous driving technology to the four corners of the earth: its native Sweden, the U.S., and, starting in late 2015, Australia. The automaker has capitalized on the Australian Driverless Vehicle Initiative for the testing of its self-driving fleet, plying long, lonely outback roads with the aim of finessing its technology into something marketable.

While Volvo expected its available Large Animal Detection system to keep driverless vehicle occupants safe, Australia ain't Sweden. And kangaroo certainly do not behave like moose or elk. According to the Australian Broadcasting Corporation , the manner in which the bouncy animals travel - in the air, mostly - completely confuses the collision avoidance system.

Large animals have a knack for causing bone-shattering, roof-crumpling crashes, so Volvo's 90-Series vehicles employ a forward facing camera that matches animal shapes to a database of creatures. After measuring the distance between the vehicle using radar, the system automatically applies the brakes as needed. Unfortunately, kangaroos, besides being nature's pogo stick, are the closest thing we have to a real shapeshifter. Also, they're rarely ever seen standing motionless.

"We've noticed with the kangaroo being in mid-flight … when it's in the air it actually looks like it's further away, then it lands and it looks closer," said David Pickett, Volvo Australia's technical manager.

Volvo's system use the ground as a reference point. When a kangaroo leaps into the air while crossing a road, the confused car might assume there's no need to take evasive action.

"We identify what a human looks like by how a human walks, because it's not only the one type of human - you've got short people, tall people, people wearing coats. The same applies to a 'roo. If you look at a 'roo sitting at the side of a road, standing at the side of a road, in motion, all these shapes are actually different."

The kangaroo detection problem needs a solution before any automaker can sell an autonomous vehicle in that country. Still, Volvo isn't swayed. Pickett believes the company can overcome the issue and that the eventual proliferation of driverless vehicles will go ahead as planned.

This article first appeared on thetruthaboutcars.com