UDV study: Physical buttons, touchscreens and voice controls compared
A German UDV study of 130 drivers finds physical buttons safer for urgent controls, while voice commands have their own weaknesses.
One second spent searching for a function in a car menu means travelling almost 14 metres at 50 km/h without fully watching the road. At 100 km/h, that distance becomes 28 metres. Germany’s insurer accident research organisation UDV examined which car controls distract drivers least. Its conclusion is nuanced: physical buttons, voice commands and touchscreens suit different tasks.
Published on 14 October 2026, the study included an experiment with 130 experienced drivers performing additional tasks using steering-wheel buttons, a touchscreen and voice commands. Distraction was measured with the standardised Lane Change Task under ISO 26022, assessing drivers’ ability to manoeuvre while using an in-car interface.
Why physical buttons remain essential
Researchers examined not just the input method but control placement, size, tactile feedback and ease of use without looking down. The study considered a range of interface characteristics affecting attention. Its central finding was that no single control method works best for every vehicle function.
For indicators, windscreen wipers, lights and hazard warning lights, physical switches and stalks are preferable. Drivers can remember their positions, while a perceptible click confirms operation without another glance. Such controls should sit in familiar locations and be identifiable by touch.
Touch-sensitive buttons without tactile feedback are particularly problematic. Even on the steering wheel they can require visual checking. Yet too many conventional buttons are not automatically better: tiny, similar or tightly grouped buttons also draw attention away.
For complex but non-urgent tasks, UDV recommends voice control. It works well for calls, music and entering navigation routes because drivers can keep their eyes on the road and hands on the wheel. Touchscreens come second for these tasks if the required function is quickly accessible without navigating many menus.
Half of users reported voice-control errors
Voice assistants are only as useful as their speech recognition. A separate representative UDV survey of German motorists found that 54% of drivers had a touchscreen in their car, and 84% of those owners used it at least occasionally. Roughly one in three touchscreen users had experienced confusing menus demanding too much attention while driving.
Voice control was available to 45% of surveyed drivers. Of those, 83% used it at least sometimes, but about half had experienced misunderstood commands or no response at all. Repeating instructions can prolong distraction, while switching from voice to touch can erase the original benefit.
The samples must not be confused. The representative online survey, conducted from March to April 2026, involved 2,004 people, including 1,578 car drivers. A separate simulator test involved 130 people. The percentages come from survey responses, not the 130 simulator runs.
UDV director Kirstin Zeidler warned about a false sense of control. Drivers often switch their gaze between the road and the screen, believing they are still monitoring traffic fully. Important events can go unnoticed during these visual interruptions.
How to assess a car before buying
Researchers recommend assessing control ergonomics when choosing a vehicle. A large central screen and extensive digital features do not automatically mean greater convenience. What matters is how quickly everyday actions can be completed and whether they require looking away from traffic.
Before buying, try everyday scenarios while the car is stationary: activating the wipers and hazards, adjusting volume without hunting through menus, and counting the steps to enter a navigation destination. Critical controls should be in expected locations and recognisable by touch.
Try the voice assistant under realistic conditions, with music playing, passengers talking and normal background noise. A reliable system should understand natural commands, avoid repeated attempts and permit quick cancellation. Unreliable recognition reduces its advantages.
For touchscreens, UDV recommends large touch targets, placement near the driver’s natural sightline and rapid access to frequently used functions. Complicated multistage menus, tiny buttons and repeated scrolling raise distraction risks. Pop-ups should not obscure critical warnings or instruments.
The research does not call for abandoning touchscreens altogether. Physical switches fit some tasks, voice commands others, and touch controls are acceptable for certain functions. UDV also stresses that reliable figures for crashes directly caused by specific interface types are not yet available.
The practical lesson is about time spent operating controls, not screen size. One second of distraction at 50 km/h covers almost 14 metres. Testing the control layout deserves as much attention as driving position, visibility or braking performance.