I'm not so sure that's an optimal solution. If you are going to use the display to show the UI, you may as well just use touch interface, as long as it is responsive enough. Physical controls make more sense when they are optimized for ergonomics so that they can be used without looking.
> If you are going to use the display to show the UI, you may as well just use touch interface
This is just absolutely not true in practice.
Many synthesizers have the described design where you have a set row of knobs or buttons and what those controls do changes based on the current mode or state. A screen tells you the current function of each control.
It is much easier to build up muscle memory that lets you grab the right control and do what you want than it would be if you had to interact with the screen itself. The difference is so stark that it's hard to even explain if you haven't experienced it first-hand.
And this is for musical instruments used in live performance, often in the dark, where muscle memory and interacting instantly and correctly is vital.
Exactly, trying to use a software synth without some sort of hardware interface with physical controls becomes a nightmare very quick in any situation that isn't just sitting on your computer at 12am leisurely editing synth patches.
The same it turns out is true of steering a multi-thousand pound metal rolling deathbrick.
Even those kinds of modal interfaces with physical knobs/switches/buttons are often regarded as clumsy and aggravating compared to knob-per-function interfaces where everything control does just one thing and always that one thing.
I think the point here is that most people who use the interface a few times will learn the necessary key sequences. This learning can happen with the car at rest, and after that the user can keep their eyes on the road. It's not perfect, as some people have a slower learning rate than others, but it's sure better than a touch screen.
Well, if the control all change in meaning depending on the interface state, you can only memorize sequences if there is a reset somewhere. And those will probably be very cumbersome sequences.
A "home" is a reset. A "back" button won't solve the issue.
On a second thought, if the options are hierarchical, the sequence of clicks may not be cumbersome at all. Also, in a car the state can be something really easy to keep track of, like "the car is running", but even then, I'm not sure it's safe to rely on this.
