Because cars. I mean, there's pages and pages to write, but basically it boils down to that. The bicycle existed before the car, will probably exist after it,

Because cars. I mean, there's pages and pages to write, but basically it boils down to that. The bicycle existed before the car, will probably exist after it, but at least when cars and fuel was cheap, people preferred cars. So the infrastructure was and is built around cars. And car manufacturing, repairs, etc., are probably a trillion-dollar industry, so they are not really interested in anything that rocks the boat, and influence the political process to try and ensure this. So on one hand you have a public that says, basically, "my car from my cold, dead hands", and on the other hand you have a giant industry which employs a significant number of Americans saying "we want to sell you those cars". It's sort of surprising there is any other transportation infrastructure at all. It's not surprising the places you find the most alternative modes of transportation are where fewer people own cars. (E.g. NYC in particular, which I believe has the lowest rate of car ownership in the US.) There's a chicken-and-egg problem at work to get anything else funded. Expecting the political process to lead us to a solution is, IMO, a mistake. The political process in the US lags behind public opinion by design, it does not lead (and often screws up when it tries). Public opinion needs to change first, then funding will change, and then infrastructure will change.