UK tube trains have two sizes - tiny and very tiny. But that's not surprising given that British Rail clearances are probably no bigger than Chicago CTA.
As a former near-Cinci resident for four years, I was always interested in those tubes. From what I understand, the money was appropriated to build the tubes but not for rolling stock or street-level ROW past the tubes exits toward the suburbs. Someone got a bee in their bonnet over costs, and it all got canceled around the time the tubes were finished.
In today's Cincinnati, the tubes don't necessarily line up with current commuting patterns from what I understand, although the downtown is undergoing a significant renaissance. In 2000 nobody went downtown, that's changed a lot.
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