I used to volunteer for a local eco group - my job was to go out and take pictures of road kill.
Pictures were used to identify and count - a very good indicator of how many of a certain species is in a given area.
If you've got a lot of them on the road - you've got a LOT of them period. Most will stay away from the busy roads.
Got a lot of funny looks while taking pictures of squashed animals.
These days I'd probably be arrested as a terrorist.