PARIS—The first self-driving cars will be seen on roads in 2018 in a few countries set to pioneer the technology, including the U.S., Japan and France, Carlos Ghosn, the chief executive of French auto maker Renault SA, said Tuesday.

These first self-driving cars will be partly autonomous and car owners will have the choice to drive themselves or use several different degrees of automation, Mr. Ghosn said, during a presentation to industry executives and reporters in Paris.

...