What is funny is I checked today's Cardinal which was already an hour plus late leaving Indianapolis this morning and yet according to the Amtrak web site itself, says it's "estimated" to be into NYC 9 minutes EARLY. Are you kidding me, I doubt that train has ever been early at any of it's stop and today's train hasn't even hit it's normal hour plus delay in the WVA/VA area. What is Amtrak thinking...
First off, Amtrak's ETA is based on the idea that the train won't encounter any more delays. So if the train is 43 minutes late right now, it assumes it will remain 43 minutes late. I suppose Amtrak could just assume the train was going to get even later (by some random amount), but that would be just as likely to be inaccurate.
As for how the
Cardinal could be an hour late at Indianapolis and still be early into New York, that's because of schedule padding. That happens on every route. The
Capitol Limited, for example, is scheduled to take 60 minutes to get from Rockville to Washington. But it's only scheduled to take 24 minutes to get from Washington to Rockville. The MARC afternoon train #877 (the Martinsburg Express) gets from Washington to Rockville in 26 minutes, with an intermediate stop at Silver Spring.
So, what you can see is that the actual travel time from Rockville to Washington is only about 25 minutes. If the
Capitol Limited arrives in Rockville on time, it will get into Washington (without further delay) 35 minutes early. If it arrives at Rocville 30 minutes late, it will still get into Washington 5 minutes early. The same can be true of the
Cardinal. When I took it last year, we lost an hour in South Chicago due to a medical emergency, but we still ended up getting into Washington only 5 minutes or so late.
But you are right that the
Card has awful on-time performance.
#50 was not on time once in May 2012, and has been on time only 20.7% of the time in the last 12 months.
#51 was on time 38.5% of the time in May 2012, and has been on time 64.1% of the time in the last 12 months.
EDIT: Clarity.