Saving over 2 minutes isn't chump change.
While the time savings is the benefit that the public will most likely notice ... the important benefits are in the resilience and capacity improvements.
Could we (could I?, no, feeling ultra lazy LOL) get a document with the goals, whatever it is, say 2:15 run time for Avelia service NYC-D.C., and the estimated Billions needed to reach that time goal.
The current schedule has a 2:46 run on a couple of Acela departures, but most claim 2:53 end to end.
Take the current time, 2 hrs 53 min, subtract the goal, say 2 hrs 15 min, gives us the savings needed to make that goal, or 38 minutes.
I can't remember the last estimate for this segment, but I'm too lazy tonight to search for it. So, I'll estimate $38 Billion in upgrades needed, for a cost of a Billion per minute.
Now where we gonna get 38 minutes of time saved?
The new Portal Bridge between Newark and NYC is ready to go, needing about a $1.5 Billion investment for 1 minute of time saved. Then adding tracks thru the marshes between Newark and the Hudson Tunnel entrance, another $1 Billion and another 1 minute. Optimists say the new Gateway Tunnels could save 2 minutes, with a preliminary estimate of $24 Billion. A new Susquehanna Bridge could save 1 minute and cost $2 Billion. Constant tension catenary, signaling, undercutting the tracks etc will cost more Billions.
Should this list include the new Avelia equipment or only fixed infrastructure? I'm stumbling a bit here without more work to get better figures, and I can't get a good number for cost per minute saved. But by the seat of my pants, the estimated $4 Billion for 2 min 30 sec from the new Baltimore tunnel does not seem out of line for helping to reach 38 minutes saved to meet a 2 hr 15 min running time goal.
That's before giving value to replacing the 100-year-old tunnel before it collapses, and the added capacity allowing many more Amtrak and MARC trains in the future. A project giving good value for the $4 Billion.