Rich, as mentioned, that document is just one of many from CBO, across a multitude of investigations. Are you suggesting that in the past 39 years, Amtrak has somehow come to a better place, than when it was prior to 82? Last I checked, airfare is still better priced to go from point a to point b in most locations that Amtrak could transit you to... which STILL lines up with TCtO per seat mile. DCA to Boston is 99$ roundtrip. By Amtrak? 220. And flight is a lot faster.
I still stand by all the data out there, which has consistently, over many decades, shown that federal investment into Amtrak is not producing results. Unfortunately, this is not a problem that can really be solved in a short term project. It is just a sad reality.
Re: roads being a 0 RoE, this isn't true, since gas taxes in some states are used to support road infrastructure. Cant drive a car without roads, and if you are driving a car on roads, you are buying gas, and feeding taxes into the infrastructure pot for that state. Sadly, not all states do this, and as a result there are some places where the term "road" is very loosely used. Bare earth, mixed with occasional spots of asphalt or cratered concrete, definitely doesnt fit it for me. Im lookin at you, rural PA! 
edit:
Rich: https://www.cbo.gov/budget-options/54773
It is government discretionary funding forecasted to 2028. This took literally 2 seconds to google: (google search: "site:cbo.gov amtrak")
excerpt:
The federal government subsidizes intercity travel in various ways. For example, the National Railroad Passenger Corporation—or Amtrak—received appropriations of about $1.5 billion in 2017 and $1.9 billion in 2018 to subsidize intercity passenger rail services. The 2018 figure includes $650 million in grants for the Northeast Corridor and debt service and about $1.3 billion in grants for the national network that Amtrak operates. For comparison, Amtrak's capital spending in 2017 was $1.6 billion and its operating expenses totaled $4.2 billion (including $0.8 billion in depreciation and amortization costs).
That is a LOT of subsidy.
