• Automakers
  • Vehicle Design
  • User Experience
  • HMI

We Need to Reverse on Touch Controls in Cars

Sam Abuelsamid
May 24, 2024

Guidehouse Insights smart car

Human-machine interfaces (HMIs) are an underappreciated aspect of automotive safety. Driving is a remarkably complex task, and the fact that most people are able to accomplish it as often as they do without crashing is a testament to our mental resilience. Unfortunately, in recent years the progress we have made over the past several decades on road safety has stalled for many reasons, including HMIs that are getting worse and contributing to distracted driving. One of the key failure points is touch screen controls.

Touch controls actually debuted in the late 1970s on the low volume Aston Martin Lagonda, and then CRT touch screens arrived on General Motors vehicles, including the Buick Reatta, in the late 1980s. But it wasn’t until the 2000s—when LCD touch screens arrived, followed by near-universal adoption of smartphones—that touch controls became common. By 2010, automakers were beginning to talk about new vehicles as smartphones on wheels, and then it all went downhill for the HMI.

The 2012 introduction of the Tesla Model S brought many great innovations, including over-the-air updatable software and DC fast charging, but it also ushered in a shift in HMI design. Most of the interior buttons and switches were eliminated and replaced with controls on the 17-inch touch screen. Engineering, manufacturing, and assembling a vehicle interior with dozens of buttons, switches, and knobs is very costly. Replacing those controls with touch targets on a screen is much simpler and cheaper. Unfortunately, it’s also a much worse experience for driving.

As mentioned, driving is a complex task with a huge cognitive load. We know that distractions, whether it’s dealing with a child in the back seat or being alerted by a phone, draw the driver’s attention away from the road and can lead to crashes. Prior to touch screens, many common tasks like adjusting radio volume, temperature, or fan speed could be accomplished by muscle memory, reaching down with one hand to twist a knob or push a slider while keeping eyes on the road.

When those same functions are embedded in a touch screen interface, the driver must look at the screen to see the touch targets. Reaching out while driving, one’s hand inherently tends to move around, requiring even more attention to tap those targets.

Unfortunately, for many automakers including Tesla, Rivian, and now even Lincoln, the trend is getting worse. On recent models, Tesla has eliminated the transmission shift and turn signal stalks and put them in the screen along with ventilation controls. Vents should be easy to adjust by simply grabbing a little handle and pointing it to make airflow comfortable. Instead, on the new Lincoln Nautilus, it requires fidgeting with a screen interface.

Recently Angela Chao, sister of former US Transportation Secretary Elaine Chao, died in her Tesla Model X when she inadvertently backed into a pond while trying to shift into drive through the touch screen. Chao had reported having issues with the touch screen gear shift previously, and at least a dozen complaints have been filed with the Department of Transportation over similar issues. Chao’s fatal crash is just one example of the mode confusion that can occur with touch interfaces.

Fortunately, at least some automakers are trending in the right direction of retaining or restoring physical and tactile HMIs. General Motors features dedicated controls in most of its new generation EVs. Hyundai and Volkswagen have both recently showcased updated and new models that are shifting back from touch-based controls to more tactile HMIs, to be launched beginning in 2024. Technology has added a lot of good things to the automotive landscape over the past several decades, but designers and engineers also need to consider areas, like the HMI, where the old ways actually work better.