Chris Woodyard

USA TODAY

Tesla Motors' CEO Elon Musk has seen the future and it's about self-driving cars -- for everybody.

"All cars will go fully autonomous in the long-term," Musk said in response to a question on a call to comment on the electric automaker's third-quarter earnings.

In fact, it will be "quite unusual to see cars that don't have full autonomy" in a 15- to 20-year time frame, he said. Sooner, he says, for Teslas.

Why will self-driving car be the de facto choice of all new-car buyers? Because those cars that steer the old-fashioned way, by hand, will be deemed so inferior that they have will "negative value."

He added, "It will be like owning a horse" -- nice for sentimental value, but not terribly practical for transportation.