[thaumaturgy]

That's the result of a combination of two things: aircraft don't often have one of the major problems that cars have (dense traffic and other obstacles), and that the problem of dissimilar surfaces was solved, for aircraft, by making the surfaces more similar. Cars instead have to be able to negotiate a variety of terrain.

So, safely automating cars is a harder problem, but not because the car itself is a more complex vehicle.

[gaius]

A harder problem requires more complex software, no? The complexity of the vehicle itself is actually not a factor.

[thaumaturgy]

Oh, you're right. Somehow I misread your earlier statement as being about the complexity of the machines themselves.

I agree totally with you then. Even accounting for avionics, control surfaces, target acquisition, and so on and so forth, automating cars is a much harder nut to crack, software-wise.