California and Nevada have already created legal scaffolding for operating autonomous cars. Certainly the legal issues will get very interesting, but I don't think they'll get in the way of the autonomous cars. Just look at how well Uber is doing! Get a product people want, and sometimes the law will bend pretty far.

The private property restriction is only for Batmobile mode where you summon the car and it drives to you all by itself.

The autopilot / cruise control 2.0 / lean back mode where it handles all the driving on the highway, but you're still behind the wheel.. That's the main thing. I'm also curious whether there are state law issues.

According to the article, it will self-drive on "highways and major roads," and the "summon my car" is only for private property.

Maybe it's just adaptive cruise-control combined with lane keeping, and you'll still need to make turns.