I don’t think you will get that much sleep as the car veers trying to avoid hitting deer running across the road, or tore up tractor trailer tires bouncing and flying towards the car, or just thinking about the possibility.
Considering that the car would have sensors, it could probably do a better job of avoiding the deer than you. I’d be more concerned about adverse road condittions, than anything else.
I’ve worked with robotics and know the cars would be just fine if you can eliminate all the variables that would interfere with them. Unfortunately you can’t eliminate the variables without putting dedicated roads inside sealed concrete tubes.