Gee, my joke sure gets around. 
Can be nasty for the elephant victim upcountry if it’s a bus or lorry. But in the city, the poor beasts get smacked by cars from time to time and get a broken leg or something. Sad. More reason to keep the elephants out of the city.
squirrel in Dearborn, Mi.
Southern England: foxes, pheasants (in season), badgers. The “classic” roadkill as used in cartoons is the hedgehog, but they’re less common than they were. (I did stop a few months ago when I was on my bike to give a hedgehog a helping hand up the kerb to stop it adding to the stats though.)
In autumn, it’s definitely pheasants. They breed loads of them for shooting in this area and they are the most clueless creatures. I really don’t see how hunting pheasants is any kind of challenge at all. They are (a) slow, (b) noisy, and © brightly coloured. What’s more, they won’t stay hidden in undergrowth and let people pass, but will instead wait until you are a few feet away and then squawk loudly and lumber slowly into the air. You could catch them with a butterfly net, never mind a shotgun.
Skunks.
Types of bird: pigeons, sparrows.
My town is lousy with squirrels and they don’t seem to be getting any smarter wrt traffic.
Sure they are. You only see the dumb ones in 2-D.
Possums, cats, and squirrels. I did see a beaver last week, though.
I hate chipmunks only because of their tiny holes throughout the yard! I can certainly sympathize with you if your horses and livestock are falling in squirrell holes! I think that would make me s hoot the cute little bastards! Chipmunks I drown in a 5 gallon bucket, half filled with water and covered with sunflower seeds. The chipmunk swimming pool!
In my immediate area in Florida, elderly pedestrians have to rank pretty high on the road kill list.
Other: squirrels and skunks.
I live in a city so it’s mostly pigeons.
Squirrels.
Skunk.
Deer and turkey are common but probably squirrels are the most numerous. I’ve seen possums and skunks only rarely. Once I saw a coyote!
Another vote for squirrel.
Here in Athenstown, we have many tall oaks and no way of decreasing the population other than feline predation and vehicular impact. Those critters breed twice a year, so we get a new batch of ignorant squirrels regularly enough that my street is rarely clear of one ore more decaying corpses.
I like to think of it as evolution in action.
Yup, squirrels here too, with cats in second place. 
Mostly raccoons and posums. I stepped in one of the latter once. Had to throw the sock and sneaker out.