The low-hanging fruit is regional rail. Caltrain, LIRR, et cetera. That together with a robust metro system that links parking garages and airports is the realistic multi-modal transport we need.
Too many rail projects seem to have been prosecuted by purists who are anti-car or anti-plane. That leads to bloat, or ignoring designs that would increase real ridership (e.g. adequate parking at endpoint, or RORO stock).
The State of North Carolina runs several trains a day between Charlotte and Raleigh (The Piedmont). It runs along the same tracks as Amtrak's Carolinian. The Crescent, Palmetto, Silver Meteor and Floridian aren't focused on North Carolina but make stops in the state.
I've ridden the Piedmont a couple of times and it's very convenient compared to driving, especially during inclement weather. Could it be better? Yes - especially in Charlotte where they have a half-completed station in Uptown while the current station is in a sketchy industrial area and isn't convenient for anyone.
Once Charlotte Gateway station is completed it will link Amtrak service with local commuter rail and streetcar service (and bus/ride-share).
I recommend taking a look at Newsom's proposal for a regional program unifying San Joaquin Valley, Sacramento, and the Bay Area into a single unified rail system along with expanding ACE to Modesto a couple years ago - that would have been a game changer, but the purists struck along with other more politicially palatable options.
> Too many rail projects seem to have been prosecuted by purists who are anti-car or anti-plane
Exactly! And a la Tsebeleis, they are a significant veto player that are functionally turning a stag hunt into a Nash equilibrium.
Is the frequency and reliability of the attached rail service sufficient? Park and ride can work pretty well, but you do need a reliable rail service attached to it.
Though, also, the trouble with park and ride stations is that there's a very specific utilisation at which they work well. If they get too popular, that is also a problem.
Too many rail projects seem to have been prosecuted by purists who are anti-car or anti-plane. That leads to bloat, or ignoring designs that would increase real ridership (e.g. adequate parking at endpoint, or RORO stock).