Which U.S. City Has an Incomplete Subway System beneath Its Streets?

The Ohio city of Cincinnati almost had a rapid-transit system. In fact, roughly two miles (3.2 km) of subway tunnels still lie under Central Parkway on the edge of the city’s downtown, surprisingly well-preserved after almost 100 years of neglect. The plan for a 16-mile (26 km) loop was originally estimated to cost $12 million USD, and $6 million USD in bond money was spent to secure rights of way and build tunnels, stations, and bridges. However, by the late 1920s, the city’s will to finish the project waned -- blamed on escalating costs, inflation, the collapse of funding, political bickering, and the onset of the Great Depression.

A tunnel leading to nowhere:

• As of August 2016, the abandoned tunnel was being used to house a relocated water main and some fiber optic cables.
• In 2008, it was estimated that it would cost $2.6 million USD per year to continue maintaining the tunnels, $19 million USD to fill the tunnels with dirt, and $100.5 million USD to revive the tunnels for modern subway use. Relocating the 52-inch (132 cm) water main would cost $14 million USD.
• “We’ve had people approach us about using the tunnel for everything from grain malting to a water bottling operation, to nightclubs,” said Michael Moore, director of transportation and engineering for the city, in 2016.