Before looking at autonomous cars and planes, the question I would ask is where are the autonomous trains? Anyone who's ever had a model railway and a bit of skill with a soldering iron knows it's very easy to make a train obey signals, and stop at the station. no steering required. no route planning required. And yet we still have a squishy human who looks out the window and says 'green means go' no thinking required.
there's the novelty of the docklands light railway, and the little trundle train at Stanstead, but none of the main lines or the underground are autonomous.
Is it, that we know humans sometimes make mistakes, but we also know that computers crash every single day. We are constantly being told to turn it off and on again. Most people on here know that Airbus and Boeing don't run on Windows, that there is redundancy and safeguards etc, but the general perception to the public is that computers crash, all the time.