When cruise control became most common in the 1970's or so
it would not lock in a speed less than like 45 MPH.
To be used only for highway open road.
That was a safety feature, that it could not be used in town.
Many city's have laws against using cruise control in town.
The cruise control now days can lock in at speeds above 25 MPH.
If drivers are busy on the phone or texting, how do they watch their speed ?