There was also a specific path of development that many cities took in the mid-20th century that make public transit development now very difficult. Carving up

There was also a specific path of development that many cities took in the mid-20th century that make public transit development now very difficult. Carving up downtown areas of cities with Parkways/Expressways/Highways, pushed heavily by influential urban planner Robert Moses in New York State, and copied in many other major US cities, makes it difficult to move from one area of a city to another without a car. The building of massive, unattractive public housing projects, and the hollowing out of urban areas due to redlining and “white flight” to the suburbs, now leave huge swaths of urban cities with decades of underinvestment. And finally, you have the massive suburbs, that take more money to build and maintain than they put back in through taxes, which causes a parasitic drain on the urban centers funds to spend on improved transit that isn’t focused on more car infrastructure to “keep up” with more and more cars streaming in and out from those suburbs.