The US interstate system is incredible extensive, uniform, and well-maintained (relatively speaking). States love federal dollars, and if there were federal dollars for train lines, they'd fall over themselves to get them. That doesn't seem to happen for a lot of reasons. It seems like there are a lot of corruption problems that seem to eat up train projects, but for some reason the interstate system, though replete with plenty of boondoggles, is an unstoppable road-spreading machine.