What just happened? It might be quite a few years before fully autonomous vehicles start populating our roads in large numbers, but it will happen eventually. For car lovers, there’s a worry that the introduction of these self-driving machines will lead to the decline of traditional, human-controlled alternatives. According to a Ford executive, however, this won’t happen, because autonomous cars will only last four years.

John Rich, the operations chief at Ford Autonomous Vehicles, told the Telegraph that consumers needn’t worry about cars falling out of fashion in the future. “The thing that worries me least in this world is decreasing demand for cars. We will exhaust and crush a car every four years in this business,” he told the publication.

Pittsburg-based self-driving car startup Argo AI received a $1 billion investment from Ford back in 2017, and in July this year received a $2.6 billion commitment from Volkswagen. The company has been testing its technology with Ford vehicles in several US states, including Pittsburgh, Detroit, and Washington. With 200 engineers from VW’s autonomous car unit now on its staff, its efforts in this area will no doubt accelerate.

Rich argues that as self-driving cars are cheaper and more efficient, they would be used a lot more than today’s private cars, thereby increasing the amount of wear they receive.

“Every shred of evidence we’ve seen says that as you drive down cost per mile the miles traveled goes up,” he said. “You start to help under-served populations [and] you start to move a lot more people.”

The Telegraph notes that Ford, the fifth-largest automaker in the world, is one of many vehicle companies experiencing falling sales. The six million cars it sold last year was down from 6.6 million a year earlier, as ride-hailing apps increase in popularity and fewer young people rush out to purchase vehicles.