Touchscreens that are huge are somewhat less of an issue because tap targets are much bigger. But most non-luxury vehicles come with 7 or 8 inch screens, so tap targets are small/clustered. Layer on that the fact that many screens aren't capacitive (and instead require a certain amount of pressure from your finger/fingernail), and things get even more annoying/dangerous.
With physical buttons we can keep eyes on the road, one hand on the wheel and the other one looks for the right button. With a touch screen we have to look at the screen, hoping we made the right decision about what's going to happen on the road. If there are laws against texting there should be laws against using touchscreens when the car is moving.
Just how many controls are you manipulating that are not duplicated to your steering wheel on your drive? Modern cars feature nearly automatic everything, set and forget.
Just a note about laws against texting. So my state recently, finally last year, put in place a law which said you must use hands free.
Guess what happened, now half the dolts have their phone mounted to their windshield in their field of view or on their dash. So yeah, its hands free but even more distracting. Apparently this loop hole exists in many states!
Fitts’s Law is really relevant here, even if the buttons were physical, but especially if they are touch based. Not all hit targets are the same in terms of safety.
"Somewhat" is not really good enough given the stakes. You cannot "feel" your way through a touchscreen interface and you cannot rely on muscle memory. You will take your eyes off the road to see where the button is and "aim" at it. And a bumpy road just makes it worse because it only takes an accidental light touch to trigger some random function close by.
Even a 17" screen or great UI won't fix the problems, they will just ameliorate them.
The are functions that just fit better into a touchscreen experience, and some that should have physical buttons even if it takes regulation to make sure of this.
I have a Tesla and previously owned a Lexus, I find that in practice it's pretty much identical with respect to taking eyes off the road. The only on-screen setting I ever adjust while driving the Tesla is the AC and in my Lexus I also make a quick glance down at the console because the row of buttons controlling AC functionality all feel the same.
After a few weeks of using any car I owned I basically stopped needing to look at the buttons. Even when there's a row of 4-5 identical physical buttons I just run my fingers across the row, this is where muscle memory comes in (like blind typing). The huge advantage being I can touch every button without triggering the function until I press.
I mean I'm not against huge screens in the car, as long as I can turn them off or dim them to the point where I consider they don't impede my driving. But I'd still very much like to see basic functions of the car tied (also?) to physical buttons. Whether the manufacturer also wants to put them on a screen that's fine but I see no good reason a handful or buttons and knobs can't fit in a car. The minor savings or the wow effect don't really offset the downsides of distracting attention.
> I'm not against huge screens in the car, as long as I can turn them off or dim them to the point where I consider they don't impede my driving.
This is an excellent point. Screens always emit more light than analogue gauges and buttons. When driving at night, dashboard lights annoy me so much that I avoid turning on the high-beams because the blue alert cluster light is so bright. I went so far as to wire up the dash lights to a toggle switch so I can shut them off independently of the headlights. This is on a 2003 VW Jetta, which has no back-lit screens.
