Over at the Broadtop railroad they are tracks with both the three feet narrow gage of the Broadtop line and 4'8 1/2" standard Gage line (You end up with three rails, one common rail, one at three feet and third at 4'8 1/2").
Anyway, while I did mention the LRVs, LRVs can be made in standard Gage (and most are in Europe and other places where LRVs Operate). My point was such size cars could be used, not the actual LRVs used by PAT. I would opt for the Electric drive of the LRVs, but there is nothing that says Amtrak can not run a diesel single car unit like those made by Colorado Rail Car Company. I hate to say it, but such single car trains running more frequently will solve many of the problems of Amtrak. For example while on-time service may stay what it is now, the fact you are running more trains means people may not have to wait as long for a train to come along.
I once looked at how I would operate such a system. The biggest problem is the time to travel between New York City and Chicago via Philadelphia. The ideal time to operate in New York City and Philadelphia forces the train to hit Pittsburgh and Chicago at times when people do NOT want to travel. The Only solution is to run them 24 hours a day, every 1-2 hours.
Lets look at some numbers to explain what I mean. Any train that goes from New York City will hit Pittsburgh 9 hours and 15 minutes later, and then Chicago 9 hours later. Thus this train if it operates on time will travel 18 hours and 15 minutes. If it leaves New York at 5:00 PM for the evening Rush Hours, it hits Pittsburgh 1:00 AM and Chicago 10:00 AM. Not bad for Chicago, but terrible for Pittsburgh. If you leave to earlier you get to Pittsburgh and Chicago earlier, but you have the same problem, the train hits the wrong time in the area between Philadelphia and Toledo to be of much use in those cities. On the other hand if you run the train 24 hours a day at 2 hour intervals, you can serve those areas in addition to Chicago and New Jersey.
Worse because it took 18 hours to get to Chicago, it will take another 18 hours to get back to New York. Thus if the Train reverses it gets to Pittsburgh at 6:00 PM (Good time for Pittsburgh) but New York City at 2:00 AM.
I hate to say it the best solution is to purchase 20 trains (One every two hours with 2 spares), if you want to have service every two hour service, if you service want every one hour service, 40 trains (LRVs cost about 3 Million a Piece, the Colorado Rail Car is about 5 million a piece). Thus if you buy 40 Colorado Rail Car (Diesel powered) at 5 million a piece that is $200 Million just on train cars. Now the right of way will have to be negotiated with Norfolk and Southern but assuming no additional fees from Norfolk and Southern for us of their right of way (In exchange for use of the tracks when not is use by the Passengers cars) you will still have to spent at least another $200 millions on upgrades to the right of way (Making them wheelchair accessible would cost a good bit of money).
The above is LOW for I once ran across an estimate as to the cost of extending the LRV to Oakland from Downtown Pittsburgh, and the estimate was just one Billion Dollars, but that was for right of way, and digging UNDER the existing street system, I expect less cost for a inter-city rail system upgrade but money will have to be spent.
Thus before we even get to the issue of subsidies the actual train ticket you are spending at least $400 million dollars. I would not be surprise if the cost exceeds one Billion Dollars. In my opinion it needs to be done, but getting Congress to agree to it will require pressure from the people, and people will NOT pressure them to do so unless we have a criss. In many parts of the US we are in a transportation Crisis, and people are opting for Rail as a solution. The next step is to realize regional rail without intercity rail is a waste of time and effort. A New York City via Philadelphia Rail Passenger rail line makes sense. You hit New Jersey with its Traffic, Philadelphia and its traffic, Harrisburg, Pittsburgh, Cleveland, Toledo and Chicago.
Once that line is in place and if successful (and I believe it would be) than another line from Boston to Albany through upstate New York, through Ontario to Detroit and then Chicago. Another heavily populated area (Connecting Rails between Albany and NYC and Detroit and Toledo would complement both lines).
A third line would be DC to Pittsburgh. In fact it might be better to run one train from New York City, but then at Philadelphia run every other train to DC first and then Pittsburgh (Through the better solution might just have Connections in DC and Philadelphia with the existing train system, of course upgraded to 24 hour service, and then have the trains to Chicago from Philadelphia, DC and Boston).
Other rail lines also look good, but outside the above area the population is more spread out thus the lines will NOT be as profitable as the above three lines. Extend the Boston to DC line to Florida. Add a Charleston SC to Atlanta, Birmingham AL, Jackson MS, Barton Rouge, and to Houston and Dallas (With another line connecting Dallas with Austin, San Antonio and back up to Houston. Chicago to St Paul and West if profitable (Population starts to really thin out then. Chicago to Indianapolis and Cincinnati and Lexington Ky and then Atlanta (More a connecting line than anything else). Cincinnati to Columbus Ohio to Cleveland. Chicago to Springfield Ill, then to St Louis than to Little Rock then to Houston.
I would be hesitate to go further then the above (Except for the West Coast) for you would be building lines that serve less and less people. On the West Coast I would build a line from Vancouver via Seattle, Portland OR, San Fransisco, LA and end in Tijuana.
My point is the best solution to train travel in the US is to INCREASE the number of trains per day. You can NOT do that unless you make each train smaller. 24 one car passenger trains operated by one person is better than one train with a crew of 24. 12 One car Passenger trains are better than 1 train with a crew of 12. People will take the train if it comes at convenient times for them. The only way to make it convenient to more people is to make such trains more frequently. The only way to do so is to go to one car trains.
No my first choice is a LRV systems. LRVs are used on rail lines in Europe, but are to light to be used on US Fright line by US law (The law needs repealed). If you can not have an electric powered LRV system installed then a Diesel rail is my second choice.
Colorado Rail Car Company:
http://www.coloradorailcar.com/Broadtop Railroad:
http://www.ebtrr.com/http://www.febt.org/