Mercedes-Benz CEO Ola Källenius says touchscreens in cars could continue to grow in the future - but he believes the industry might have reached peak "low button".

As with many of its rivals, the Stuttgart firm's cars have focused on introducing large touchscreens in recent years at the expense of physical buttons.

The tri-screen MBUX Hyperscreen can measure up to 1410mm wide in some cars, making it the largest such display in any production car.

There have been complaints about the increasing number of controls moved from physical switches to the screen.

However, while Källenius acknowledged such concerns, he said: "We spend countless hours on UI [user interface]. I spend hours every year discussing this with our engineers and we joke it needs to be so easy that either a five-year-old kid or a Mercedes board member can use it. That is the hurdle, and once you familiarise yourself with it, it becomes second nature."

Källenius also cited efforts to improve voice control systems but conceded "the industry as a whole might have gone a little bit too far" towards digital controls.

He noted Mercedes has now introduced physical controls on the steering wheels in its cars and said: "Sometimes you get a bit ahead of yourself and do technology for the sake of technology and maybe forget a little bit about the customer. So from now on, you will see us reintroduce the most sensible buttons."

Asked if that meant the car industry had reached 'peak screen', Källenius said: "I don't know if we're at peak screen, but we're at low button."