People have never been entirely satisfied with their own natural abilities to overcome distances and to move from place to place. Citius-altius-fortius (faster-higher-stronger) is not just the Olympic slogan that comes into play every two years, it is a summation of basic human urges. It is applicable to urban transportation needs in all situations, with the further caveats that we also want to have free choice about when to travel and with whom, and that we wish to do all that in reasonable comfort and within an affordable range of costs.

Before there were automobiles and bicycles, there were horses, camels, and sedan chairs (but only for the rich and powerful). Just about every culture at any time in the history of civilizations has had legends and fairy tales that envision flying carpets and seven-league boots magical devices that allow some people to move fast, freely, and far. Nobody has ever given away a flying carpet voluntarily.

Homer clearly had automobiles in mind when he described in the Iliad ^[6] the vehicles that Hephaestus had forged from three-legged cauldrons:

He d bolted golden wheels to the legs of each so all on their own speed, at a nod from him, they could roll to halls where the gods convene then roll home again a marvel to behold.

As always where mechanical devices are concerned, Leonardo da Vinci thought of self-propelled vehicles in a systematic way first. Actual devices were built in the seventeenth and eighteenth centuries that utilized...