A six-mile loop of moving platforms could have been the congestion solution 1903 New York needed.
Ever wonder what transportation innovation looked like in 1903? Here's a fun one, courtesy the New York Public Library's Digital Gallery:
This design for a series of "underground moving sidewalks" ran in the February 28, 1903 edition of Harper's Weekly, alongside an article about how the city ought to be tackling congestion issues on the eve of new bridge connections bringing commuters and travelers from Brooklyn into New York City.
The key issue for the early 20th century transportation planners behind these "moving sidewalks" was to reduce congestion caused by massive crowds of people crossing the East River and to make it easier for them to get to the subway, elevated train and surface transit terminals in Manhattan.
The newest proposition to solve this problem is now before the Board of Estimate, which has referred it to the Rapid Transit Commission. It is popularly known by the misnomer, "Moving Sidewalks." It is really a system of moving platforms or continuous trains. Men like [railroad magnate] Cornelius Vanderbilt, Stuyvesant Fish [president of the Illinois Central Railroad], E.P. Ripley [president of the Atchison, Topeka and Santa Fe Railway], and others are interested in the new plan, and the engineers not only pronounce it feasible, but extremely economical. The moving platform is simply the improvement of the continuous trains that were in operation at the Chicago and Paris Expositions, and that carried millions of people along at a good rate of speed and in absolute comfort without accident.
The plan involved a loop of moving platforms running from Bowling Green at the bottom tip of Manhattan and up the east side of the island, connecting with the Brooklyn, Manhattan, and Williamsburg bridges. The system would run in subway-like tunnels about 30 feet wide, with stations every two blocks, on a six-mile loop. About 10,600 platforms would be needed for such a system, and they would be arranged with three separate tracks: two stepping platforms, one running at 3 mph and the second at 6 mph, and the main platform, which would have seating and run at 9 mph.
According to the May 8, 1903 edition of The New York Times, concerns that the moving sidewalks would be prohibitively expensive would likely doom the project, requiring unheard of 5-cent fares. Although an October 9, 1903 edition of the Times reports that the rapid transit commission recommended "immediate adoption" of the plan with a $3 million outlay, but that obviously never happened. Gothamist suggests that "Brooklyn Rapid Transit had a hand in burying the idea, as they had a monopoly on the borough's public transit at the time."
The idea was originally proposed by a New Jersey merchant named Alfred Speer in 1871, and was eventually put into action during the World's Columbian Exposition in Chicago in 1893, with a moving sidewalk designed by Joseph Lyman Silsbee. Breakdowns were reportedly common.
The design would be improved upon and installed again at the Paris Exposition Universelle in 1900. That moving sidewalk can be seen in action in this film, shot by one of Thomas Edison's associates at the exposition.
After that, the idea seems to have petered out. Smithsonian's Paleofuture blog has a nice rundown of the history of moving sidewalks – from Speer's original idea in 1871 all the way up to The Jetsons. But outside of failed urban projects from the 1900s and futuristic cartoons, the closest thing we've got to this potentially amazing public transit idea is the highly watered-down moving walkways so common in airports around the world.