The transit infrastructure (highways, bridges, tunnels, waterways, etc.) and maintenance thereof IS the responsibility of the state. That ought to be a "given."
If our states, and by extension the Federal government, would stick to their knitting, so to speak, and take care of what they are supposed to (infrasctructure, public safety, education to name a few) and not expand beyond that, we wouldn't have some of the budget issues, let alone high taxes, that we face now. But that's another story.