Researchers are calling for special tunnels and tougher road speed limits to help save Australia's koalas.
A parliamentary inquiry into the decline of the koala has painted a bleak picture for the marsupial's future if immediate action is not taken.
Scientists and advocacy groups have told a Senate committee the population of the koala is in freefall across the country, the ABC reports.
The inquiry recommended state governments introduce lower speed limits around known koala areas, install koala-proof fencing on major roads, and build more tunnels and bridges to allow koalas to cross roads safely.
There are also calls for the environment minister to consider listing the animal as an endangered species in areas where numbers have significantly fallen, more controls over wild dogs and a boost to research funding to halt the decline.
It is not known how many koalas are left in the wild - experts estimate anywhere between 43,000 to 300,000 - but the numbers are slowly falling and road deaths are the second biggest cause, Reuters reports.
Loss of habitat due to land clearing is biggest risk to koalas, which live almost entirely on gum tree leaves. Numbers have also been reduced by an AIDS-like virus which causes immune deficiency and cancer.
In Queensland, authorities reported more than 4500 koalas were hit by cars over 12 years to 2009, prompting the state government to commit to "koala-friendly" designs for main road construction.
Some areas of dense koala populations also have special koala-proof fences around major roads, and tunnels which allow the animals to cross safely underneath.