>The computer is not going to overlook even one deer.

Oh it will. Animals have evolved amazing camouflage. Computer Vision will easily miss a deer hidden in a dark treeline. And radar/lidar even more so because the forest is going to have a pretty irregular geometry.

Even identifying a bicycle in a regular city street is something we have not convincingly solved yet. Animals on the side of a forest road is pretty far away.

It isn't possible to not overlook deer because they are often doing things such that you cannot spot them. Unless you mean they won't fail to see a deer 2 meters in front of the car - but it is too late to do anything about it then.