Correct, assuming a perfectly spherical car on a frictionless road with no other traffic, hazards, or traffic controls. In the real world 20mph puts a cap on y

Correct, assuming a perfectly spherical car on a frictionless road with no other traffic, hazards, or traffic controls. In the real world 20mph puts a cap on your top speed only in the few instances you could possibly go that fast. Factor in lights, queueing at rotaries, slowing for emerging traffic, slowing for and then going around cyclists... ad nauseam