Why is the roadkill in canberra painted with big green crosses?

Question

We recently visited Canberra and would like to know why they paint their roadkill with big green crosses. I heard they leave them there to remind motorists not to speed but I cant work out why they would paint them.

Answer 1

It means that Wires (or LAOKO further south) has checked the pouch for babies.  They do it so time and effort is not wasted with several volunteers checking the same carcase several times.