At the end of WWII General Motors lobbied a Republican Congress and got the go ahead to mass market the diesel engine bus to cities, insisting that it was a better form of public transportation. Almost all US cities bought this bull crap: 1) because at the time it was less expensive than maintaining a large workforce to service and run electric trolleys, 2) transportation routes could be easily changed as the suburbs blossomed. However, in most cities the fuel burning buses rarely opened up new areas for public transit and tended to follow the old trolley tracks which were quickly covered in asphalt. At that same time, even though air travel was still "exotic" the main reasons the famous trains that criss-crossed the USA continued to lose customers were: 1) WWII had taken its toll on the railroads -- the rails and equipment were worn out from being pressed into service to support the war effort and 2) the price of gasoline was kept at an artificially low level, therefore personal automobiles seemed a more realistic and cheaper way to get around.
Trolley systems have made a bit of a comeback, but it's been an uphill battle. San Diego, which I believe has one of the better transit systems, is in a constant battle to keep their transit system alive and publically funded, despite the fact that it is heavily used, even by its opponents. The same goes for Salt Lake City, where the installation of one valley-long trolley met opposition for 25 years until better minds prevailed and the first line was built and suddenly everyone began to use it -- except on Sundays. The mormon church, which has a heavy hand in the ewetaw way of life, didn't like the idea of citizens being able to use the trolley on Sundays, because it conflicted with their idealized concept of a day of rest. Then one weekend brighter minds prevailed and, just to benefit the mormon church, the new transit system ran during one of the "general conference" specials that particular church throws twice a year, making it easier and more economical for large families to attend church in downtown SLC by taking the trolley. Of course, now the trolley system runs EVERY Sunday. But that's an example of the backward thinking that tried to prevent the return to an efficient mass transit system in the West. Now SLC can hardly wait to add new lines, including a commuter train service from Ogden to Provo.
This same scenario will continue in most 'Mericuhn cities in the future. Atlanta's got a great subway system, except that it isn't expansive enough. If you been to Portland, Oregon, and tried their trolley system the jury is in that the service is exceptional. But remember that the main reason these systems were dismantled in the early 1950's in the first place was primarily to benefit the automobile and oil industries.
Every time I return to the USA I end up gaining 10 pounds. If I were to live at my place in Nevada for a year, I'd probably become morbidly obese. Why? Because I have to drive everywhere for food and services. Interstate 80 and Highway 93 and not conducive to public transport (or even riding a bicycle). Just to buy groceries ends up being a 40 mile round-trip event. But in Barçelona, Paris, and even Bueno Aires I walk about three blocks to the nearest Metro or bus stop and can get anywhere within the city or out into the neighboring countryside. Even México City has a remarkably sophisticated Metro system that makes the "quaint" New York subway system look and run like the antique it is. Sorry, New Yorkers, but your subway system is a filthy pig sty that reeks of stale urine. But I understand that's one of the things New Yorkers like about their subway system. Regardless, even taking the New York subway means I burn enough calories walking to a station and running up and down stairs that I have little trouble keeping relatively fit.
It would be so easy to rebuild the the USA's railroads, implementing rapid passenger service that cost less than airfare and was fast enough that the extra few hours to travel between most cities (Phoenix to Tucson, for example) would not be an inconvenience. But first the oil industry has to have something major happen to it (like U$S5 a gallon gas?) and then the government has to intervene and subsidize the renovation of existing rail beds plus breaking up the mess they've allowed private railroads to create. In the west, the Union Pacific pretty much rules the rails and owns all the old routes, keeping the rails loaded with freight. That's just fine. But 21st Century rails need to be built along the same corridors so an efficient rail high speed rail system can start to grow.
I don't know about you, but it ain't gonna happen in my life time. Although, when I was a child my family regularly traveled from our little central ewetaw farm community on a trolley/train line called
the "Inter-Urban", two hours to SLC from where we changed trains at the Uniion Pacific Station and took a second train to Ogden. After a two or three hour wait we boarded a Northern Union Pacific passenger train and would usually be in San Francisco (actually Oakland, we always had to take a bus or trolley into the city) within 26 hours. Now, if you catch the same AmTrak route inm Elko (thus cutting off about 300 miles of the old trip) you still end up in Oakland and the shortened trip takes 23 hours.