DETROIT — Google’s driverless car may still be a work in progress, but the potential for semiautonomous vehicles on American roads is no longer the stuff of science fiction.

By the end of the decade, a growing number of automakers aim to offer some form of hands-off-the-wheel, feet-off-the-pedals highway driving where a driver can sit back and let the car take control.

The very nature of driving, experts say, will be radically reshaped — and the biggest players in the auto industry are now vying to capture a slice of the revolutionary market they see coming within a matter of years.

“This is the year we’ll look back on as the turning point,” said Scott Belcher, president of the nonprofit Intelligent Transportation Society of America, who has helped organize a global connected car expo for seven years. “We’re at the cusp now of this completely new generation of transportation, and it’s going to change things on a scale not seen since Eisenhower and the Interstate Highway System.”