Another really tricky and dangerous animal at night is bison. I know bison no longer roam as they did in the past, but every summer I am driving through Wind Cave National Park and Custer State Park (Black Hills of South Dakota). I can guarantee they blend in exquisitely with the highway asphalt. A collision with one - a fully grown bull weighs in the vicinity of 4,000 pounds - would be nasty.

Bison herds use the roads for travel and I can vouch that, not only "you can't roller skate in a buffalo herd" you can only wend your way through them at maybe 5 mph.