@Twig Having read (much of) the page linked by @Jonty Wareing, it's a lot less bad than it sounded. Also I've only driven manual cars, but I assume on automatics you would only need the "gearstick" (not really gears, but still) when stopped? I'm used to expecting the gearstick to be available and needing to use it at a moment's notice, but I guess this is more like a mode selector rather than actual gears, and you'd only need it when stopped. Hopefully there's a display to show whether the car has picked forward or reverse, and hopefully it's very easy and obvious how to change it if it picks the wrong one. I guess in a way this is an extension of standard automatic transmissions, where it's normal and expected that the car picks the gear for you, just in this case it's including reverse in its calculation.

This did remind me of a situation my dad got into with his car (which is also the only one I've driven recently) where he was stopped going up on a narrow hill road, trying to maneuver around another car coming down. The car has an electronic "hand" brake control, and won't release the brake unless you have your foot on the brake pedal. It has "autohold", where if the car stops while the brake pedal is pressed, it'll keep the brake on after you release the brake pedal until the clutch hits the bite point while in gear. My dad had to get out to check which bits of ground were safe to drive on, but then couldn't get autohold to work after that. He needed to release the brake while holding both the clutch and accelerator, for a hill-start, and would normally use the hand brake, but couldn't because that needed the brake pedal to be pressed! In the end, he accidentally discovered the reason: autohold is disabled (without mention) if the driver's seatbelt is not fastened! My point, I think, is that although, yes, it's good to think about all the edge cases while designing the control system and taking steps to make things safe, it's also important from the UI design perspective for the tools you're using to be *predictable*, which means *reducing* the number of rules for specific cases so that the operator won't have to remember a million different fixes for when those edge cases conflict with reality.

Like where, as you describe, there are two sets of controls, one of which works most of the time, the other is *supposed* to become usable if the first is not, but there's an obscure method of activating it in the unusual case where the first controls don't work but the system to detect that case also fails to detect it. I don't much like the idea of touch-screen controls for anynthing critical in a car anyway (what if I'm wearing touch-screen-incompatible gloves? And you can't use them without looking fully at them because of the lack of feel as to where the button edges are), but then given that it *has* touch controls with a physical backup, why make it deliberately difficult to use the backup controls? If the physical controls are there, shouldn't they work all the time? Are they a good backup if they (deliberately) don't always work? Why make people have to think about which of two nearly-equivalent sets of controls they need to use for the same function so they can't have as effective muscle memory? It just seems stupid.