(In fact, I find it fascinating that present-day Americans would see it as a creepy totalitarian idea if you proposed that cops should be authorized to stop and detain pedestrians for random paper checks, even though the same thing is considered a normal and unremarkable fact of life for drivers. This example demonstrates especially clearly how random and incoherent human intuitions are when it comes to feelings of outrage at a perceived lack of freedom or equality.)

Well... driving a car is much more dangerous (especially for others) than walking, so requiring a licence to do the former but no special requisite to do the latter doesn't seem that arbitrary to me.