According to the AA, there are on average 400 car occupants injured every year (figures released Jan 2017) in UK in collisions with deer, resulting in 20 human deaths. And 42,000 deer killed each year.

My sis in Scotland has attended at quite a few deer collisions when she was on call at night (Perthshire). Also, one event involving a Highland cow, whose horns shattered the windscreen and pierced the thorax of the unfortunate woman driver, who later died. Scottish red deer stags have huge antlers, and will attack people when in rut.

We see lots of muntjacs dead at the side of the road. And lots of fallow deer run across the road in herds, especially in autumn/winter.