This pertains to the recent PATCH article describing a possible new High-speed rail route to be built by Amtrak in the future. Here is some additional info.
The existing shoreline route has too many sharp curves that affect the large wheels of the current high speed "Acela" trains...an engineering oversight. They are trying to attract more business customers by creating faster trip times between Boston and NYC, catering to the higher paying clients and being more competitive with the airlines.
If you watch the current trains traveling through Groton/Mystic, the more conventional electric trains (with smaller wheels) seem to go FASTER through all the curves. I'm told the only safe place the high speed "Acela" trains can go well over 100 MPH is a straight track section of a few miles in Rhode Island, between Providence and Boston.
As a footnote, one of the present Hi-speed "Acela" trains doesn't stop in CT even now, while only 3 stop in New London, out of a total of 32 trains going north or south. This is the simplest way to speed the trip NY to Boston and back...by eliminating route stops. The train speed, as noted above, isn't as much of a factor with the existing shoreline route.
So again...a new inland route via Hartford with straighter runs allowing higher speeds would make the difference. It could join the older, existing straighter track route above Providence.
However, what a shame that more attention isn't being given to the concept of "light rail" to serve local transportation needs.
Somewhere, someone is kicking themselves for closing up all the old trolley interurban routes and tearing up the old rail beds.
I used to ride Metroliners from DC to NYC a lot. The fastest Acelas are no more than 4 minutes faster than the fastest Metroliner was in the 1980s and 90s. We had an "express metroliner" that left DC at 6:00 a.m. and arrived NY Penn at 8:25, getting me to an 8:30 meeting at 23rd Street.