Fully autonomous vehicles could be roadworthy within the next four years.

That's according to Ford CEO Mark Fields, who has his sights set on beating rival automakers to the punch in the self-driving car sector, Digital Spy said.

"I describe our strategy as having one foot in today and one foot in tomorrow," Re/code quotes him as saying. "We are becoming a mobility company and an auto company."

But Ford has ground to make up. Although the firm has begun testing driverless cars at Mcity, a 32-acre test layout run by the University of Michigan, rivals like Google are already carrying out road trials.

Undeterred by the competition, Fields sees regulatory and legal issues as the biggest barriers holding back Ford's self-driving cars. "Technology tends to lead all that," he said.

Ford has never been afraid to experiment with new technology. Earlier this week, the firm launched a new version of its Sync Connect that allows motorists to start their engine remotely.