Ford plans to have its self-driving network up and running "at scale" by 2021. So said the Dearborn, MI-based car company's Jim Farley, its executive vice president, to the Financial Times.

Much like GM, Ford plans to put its self-driving cars into service as a network of driverless vehicles. But GM has thrown the gauntlet down by aiming to get its own self-driving cars — which will be fully electric — on the road by 2019.

Both companies believe that autonomous taxi fleets are the future of automobiles cars, rather than personal ownership of cars. GM's president Dan Ammann has stated he sees a single robo-taxi making a few hundred thousands dollars each — as opposed to just $30,000 for from the sale of just one car

Ford's plan to have it fleet running at scale in just three years, however, puts pressure on the car maker to get vehicles past the trial stage quickly.

Autonomous taxi services are already in play in small trials such as Lyft's fleet of electric Renaults in Boston which launched in December 2017. Rival Uber has also been planning an autonomous fleet, launching trials in California and then Arizona. One of Uber's self-driving cars was involved in a fatal accident in Arizona in March, although the company's CEO Dara Khosrowshahi has stated its still committed to self-driving cars.