What’s the most successful transportation system in the world? Luther Gulick could speak with some authority. Born in 1892, he witnessed the coming of the automobile, the airplane and the New York City subway. Let others praise these, or even the lowly peddler’s pushcart. No, Gulick opined in 1956, the greatest people-mover of all time was…the elevator.

Just think of it, he marveled: it was always there when you needed it, perfectly engineered into the environment with the perfect carrying capacity and perfectly free.