Detroit - Sales of vehicles able to drive themselves will account for about 9% of global vehicle sales in about two decades, according to a forecast by vehicle industry consultant IHS Automotive.
The study focused on autonomous cars, which can drive with "no attention needed by the driver," IHS analyst Egil Juliussen said.
Such cars are not currently available for sale, but IHS predicts they will be available around 2025.
It expects global sales of self-driving cars in 2025 to be 230 000 - less than 1% of the 115m cars expected to be sold that year.
Juliussen said, however, that by 2035, sales of self-driving cars will reach 11.8 million, or 9% of the 129m global vehicle sales expected that year.
Most of these sales will be in well-established vehicle markets like the United States, Western Europe and Japan.
The pace of growth for self-driving cars will exceed that of electric cars, which have been hobbled by the high cost of batteries, Juliussen said.