Maybe I'm just ignorant, or blinded by cognitive biases, but I always imagine the combination of gas/diesel and internal combustion engines as an engineering optimum, reached iteratively after decades of wandering through parameter space. At least wikipedia's version [1] of the history of cars seems consistent with this, showing a history of dozens of engine designs and fuel choices (solids, liquids, gases, and electric batteries) long before the ICE came to dominate. (Maybe I'm unreasonably optimistic, but I'm unsurprised we've succeed in breaking free of our original "path", steam engines). Perhaps it's my lack of imagination, but I'm not aware of any practical fuel (chemical or otherwise) superior, in energy density and convenience, to liquid hydrocarbons. Nor am I aware that there was a historically superior way of obtaining liquid hydrocarbons to letting them gush out of the ground, which I understood was the least expensive source for them throughout modern history.

Am I simply rationalizing the history of modern transportation, and if so can you enlighten me as to the "paths not taken" that I'm blind to?

[1] http://en.wikipedia.org/wiki/History_of_the_automobile