Level 3 on major freeways in about two years. (Like Tesla claimed to have, but without the "slams into cars parked at the left edge of the road" bug.) Level 4, in the form of self-driving low-speed vans in campus-type areas, has already been deployed in a few locations.

Volvo loaned a family a Level 3 car yesterday.[1]

[1] https://www.engadget.com/2017/01/09/volvo-tests-self-driving...

My personal expectation is that Level 3 could be relatively soon given that companies like Volvo are doing legitimate pilots. Maybe 10 years? But the question would be how many places they would (legally) be allowed to drive without an attentive driver and under what conditions.

It's not clear to me how much L4 buys you as a consumer product. "No driver during defined use case." If you can't go door to door in a wide range of weather conditions, what's the difference between having a non-attentive driver and no driver?

ADDED: Yes, as was written elsewhere, low-speed campus use cases make sense. But that's not what most people consider self-driving.

Level 5. Many decades.