What if it suddenly veers into a wall or oncoming truck due to an incorrect or faulty instruction. Fuck autonomous!
You are obviously not an embedded system engineer with mission critical design experience. The proper way to design a system like this is to have multiple processes running on at least two separate CPUs. The most powerful CPU computes the car's speed and path, and another process running on a separate CPU performs sanity checks on the results. If something is clearly wrong (like steering into oncoming traffic), then the backup program applies the brakes and pulls off the road. Bits can be flipped by cosmic rays, or whatever, and a system like this is designed to deal with that. This is standard critical system engineering. Then you put it on the test track, and throw all the crap you can at it: turn off sensors at random, put corrupt data on the bus, flip bits in memory, etc. Keep hammering it and fixing the problems until it can handle any failure as safely as possible.