Rochester's subway was more like light rail from what I understand (i.e., what they have in Buffalo now). A large portion of it was a re-purposed aqueduct from

Rochester's subway was more like light rail from what I understand (i.e., what they have in Buffalo now). A large portion of it was a re-purposed aqueduct from the Erie Canal, so it wasn't quite the most ambitious subway system. If it had stuck around longer past the 40s though I imagine it could have evolved into quite a formidable system.