The technology for semi-driverless cars still isn’t good enough or cheap enough. The $50,000 Volvo I was driving — like a Tesla I’ve tried — got confused by unpainted lane lines, for instance, and I had to take over. But the technology is improving rapidly. Within a few years, many cars will have sophisticated crash-avoidance systems.

Has anyone driven a Tesla autopilot? My Subaru has Subaru's adaptive cruise control. It also yells at me if I stray out of my lane. I ask about Tesla because every article up to this one had led me to believe the technology was pretty much ready for prime time.

A road near home had a small median and turn lane added. The old white line was mostly ground off, but it's partially visible. My Subaru sometimes dings at me because it sees me straying over that old line as I drive around the median. My Subaru will also stop itself in traffic but locks the brakes until I brake and take over. Is Tesla further along?

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.