Keep a .22LR in your car.

[Poodleshooter]

Call a game warden. In addition to knowing what to do they can give you a roadkill tag so you can keep the meat if it is worth doing.

Probably a big "if" in most cases.
I've hit 2, and started to butcher one of those. The meat was a bit....tainted. Blood,bones, waste and guts all through the abdominal cavity. Roadkilled deer don't die easy like most shot deer do.
I was curious that time, but I doubt I'll try that again.

 

[Mannlicher]

I am speechless, and that does not often happen. I just have to ask though, was this post done tongue in cheek?

 

[enfield]

I doubt it was tongue-in-cheek. There's some really strange opinions out there in the world.

I don't hit animals intentionally. I don't risk an accident to avoid them either. I would never think of stopping my truck and going back to administer a coup-de-grace, or calling for a PETA ambulance.

(almost) Unbelievable!