[NegativeK]

> bobbing up and down hills around hairpin turns on loose gravel

They slow down. Tesla's dumbest form of automation will slow down more than a human when encountering a turn.

> How well does LIDAR cope with tall grass?

It stops and demands help. While car automation leans on GPS/nav, it won't blindly follow it -- similar to (almost all) humans.

I wouldn't want to risk anything near a vehicle accident on the road, though. But the situation is not _as_ bad as you might think.