The plan was to get parts of the line up to 125 MPH, they even put in quad gates in perperation for that IIRC. Currently the line has varrying speeds up to a max of 110 MPH in a few places.
And it won't get any faster without a lot of work to straighten out the curves. Any part over 110 mph would be so short as to be meaningless, In fact, I would not be surprised if the 110 mph segments are almost pointless as well. If they could get more at a consistent 90 mph by getting rid of some of the more crooked areas it would be more worthwhile.
Just for reference:
from:
http://safety.fhwa.dot.gov/media/twgreport.htm
The FRA's rail safety regulations require that crossings be separated or closed where trains operate at speeds above 125 mph (49 CFR 213.347(a)). Additionally, if train operation is projected at FRA track class 7 (111 - 125mph) an application must be made to the FRA for approval of the type of warning/barrier system. The regulation does not specify the type of system, but allows the petitioner to propose a suitable system for FRA review.
In 1998, the FRA issued an Order of Particular Applicability for high-speed rail service on the Northeast Corridor. In the Order, the FRA set a maximum operating speed of 80 mph over any highway-rail crossing where only conventional warning systems are in place and a maximum operating speed of 95 mph where 4-quadrant gates and presence detection are provided and tied into the signal system. Grade crossings are prohibited on the Northeast Corridor if maximum operating speeds exceed 95 mph.
I added the bold. I wonder if New York state even bothered to see what types of warnings the FRA would accept for their supposed 125 mph parts or if, like the rest of this debacle, just decided to do what they wanted to do and thought everybody else would go along with it.