>
>or decentralise so people don't commute en masse. thats an argument for not spending on that sort of infrastructure.

I read an article recently where the author made a persuasive case that one of the worst things that happened to postwar US was the development of the interstate highway system. It disrupted small towns that were bypassed, destroyed commercial rail systems and massively increased air pollution.
As someone who has enjoyed many happy hours travelling on that system my first reaction was to disagree, but on reflection I think that the author has a good point.