When people say self driving cars are on the way, do they mean rolling bedrooms where I can take a nap, or do they mean a car that will override driver commands that would otherwise result in a collision? Articles seem to imply the former, but increasingly I suspect the latter.

I think it's something closer to the latter than to the former. Google - excuse me, Waymo has shown little to no progress and is supposedly suffering from an outpour of talent. Which gives HERE (formerly Nokia, kleinbl00) and TomTom a chance to catch up on their mapping capabilities.

Full automation is a really tough nut to crack. It's an easier problem when you have low-speed suburbs (like Waymo tests in) or fenced-off highways (like Tesla, Volvo & Daimler), which is why those places see automation happen. Tesla is out there beta testing automatic steering on highways on its willing serv-...I mean users. Volvo and Daimler will probably have something similar ready in a few years as an expensive addon to their luxury cars, with it slowly trickling down to regular cars.

But full automation, in complex urban environments and non-Californian weather? The experts I've talked to about this subject are almost all very conservative in their estimations. "Forty or fifty years from now, maybe."