"Park&Ride" hubs. Rather than having everyone commuting through the same routes and bottlenecking the same roads on rush hour you could drive/cycle/walk to your local suburb hub and catch a train/tram/metro to where you need to go.

There is nothing ground breaking or sci-fi about it. It has been done many times over in several places around the world both dense and sparse.

It just needs political will and budget. The main problem you guys have in the US is how entreched lobbyists are.