PITTSBURGH—Bob Regan, a retired geophysics professor, says the time he spent counting this city's 45,454 public steps was the happiest two months of his life.

The step-smitten Mr. Regan wrote a book in 2004 called "The Steps of Pittsburgh," which includes photos and a breakdown of how many steps are wooden or cement, and the top five staircases by steps, the longest being 378 steps. With each step rising a little less than half a foot, the city's collective steps, if stacked, would nearly reach the top of Mount Everest,...