In the early 1920s, Cincinnati set out to build a modern underground rapid transit loop to relieve severe streetcar congestion and connect its suburban residential areas with the industrial downtown core. The city approved a massive bond issue to construct the Cincinnati Subway, repurposing the dry bed of the old Miami and Erie Canal into a dual-track subterranean right-of-way. Construction progressed rapidly at first: workers excavated miles of tunnels, laid concrete tubes, and constructed four fully formed underground stations complete with tiled walls, platform stairwells, and passenger mezzanine levels.
However, the project hit a catastrophic wall of financial and political crises. World War I caused severe construction delays and skyrocketed the cost of steel and labor, rapidly depleting the original six-million-dollar bond before tracks, electrical systems, or subway cars could be purchased. Following the war, political infighting, administrative corruption, and changing urban leadership stalled funding approvals.
By the time Mayor Murray Seasongood attempted to revive the project in the late 1920s, the Great Depression struck, killing any public appetite for additional municipal transit bonds. Shortly thereafter, the rise of affordable personal automobiles rendered heavy rail transit politically obsolete in the eyes of local voters. Today, the two miles of completed twin tunnels under Central Parkway remain pristine yet empty.
They serve as conduits for public utility water mains and fiber optic cables, standing as North America's largest unused mass transit system.