Train speed was a factor, the train was late so amtrak proceeded to break speed limits to catch up time (clocked at over 100 mph).
Well this so-called "freakishly uneducated" person is going to educate you. The problem is with your GPS!
In addition to the other reasons provided by many of the educated people here as to why the train wouldn't violate the speed limits; the simple reality is that the train cannot violate the speed limits. At least not for very long and not 10 MPH over the posted speed limit.
The engine's computers are pre-programmed with the maximum authorized speed for that route, in this case 90 MPH. In most cases, 79 MPH. Because the engineer, just like a driver cannot maintain a steady 55 MPH, the computer gives the engineer a leeway of 3 to 4 MPH over the speed limit for a minute or two at most. If the engineer remains above that speed limit for longer, or if he/she tries to go above that 3 to 4 MPH leeway, the computer will immediately apply the train's emergency brakes and bring it to an immediate halt.
At that point, the engineer would have to explain why the train stopped, and he/she would be relived immediately from duty.
Since that didn't happen, clearly the problem lies with either your reading the GPS or the GPS itself. And GPS isn't 100% accurate in the first place. Angle to the satellites, how many satellites, and other factors influence the speed readings of a GPS. And I'm sorry, but I do have to wonder if a bit of exaggeration is in play on your part too.
But regardless, this educated person can guarantee you that your train never hit 100 MPH!