It's one of my biggest fears when driving to Flagstaff to escape the Valley heat in the summer -- deer in the road.
Sometimes they just stand there not moving an inch even when you slow the car down to avoid hitting them. There are warning signs everywhere.
I've even seen an accident once when a car hit a deer on the highway. Not pretty. But I've never seen actual video from inside a vehicle showing an actual deer crashing through the windshield. This video out of Pennsylvania is quite disturbing.