Speed Warning Function

Why don’t all our cars have a speed warning function? On the highway, I usually try to maintain a speed between the speed limit and five miles per hour over (never more than that), and I’d like to have a button on my steering wheel that I can push (like cruise control) at any particular speed so that if that speed is exceeded, I get a soft audible “beep” every few seconds until my speed has fallen below the set point.

And, like cruise control (which I never use anymore for safety reasons), you would be able to change the set point as often as you like while driving.

Having this speed warning function would improve safety because you’d be less likely to inadvertently drive too fast, and you wouldn’t have to take your eyes off the road as often to look at the speedometer.

I can’t understand why this isn’t standard equipment on all motor vehicles.