The Air France crash over the Atlantic demonstrates exactly why auto-pilots are far from ideal. The plane got into a situation which was outside of the auto-pilot's envelope of operations. It gave control back to the pilots who were jarred by the sudden reversion to manual control, panicked and did one wrong after another.

Trains and elevators are different - they run on tracks/guides and do not have any unforeseeable obstacles, operating conditions thrown at them. Furthermore, there are several mechanical safety interlocks that will stop any out of control situations. Planes and cars have to operate under conditions with far more uncontrollable variables.

> Trains and elevators are different - they run on tracks/guides and do not have any unforeseeable obstacles

I don't think it's really true that they "do not have any unforeseen obstacles". A lot of random shit can happen on a train line, even when it's got limited access lines like the underground driverless trains linking the terminals at Hong Kong airport. I think its more that they "do not have any possible choices except go, and (try to) stop".

If a Train is "automatic" it has three tasks: start when loaded. stop at pre-determined locations. try to stop if something is detected in the way.

planes are much simpler -- the first autopilot was in 1912, the first auto landing in the 1960s.