Sometimes VHSR makes me want to scream. Danny Plaugher is a good guy, but some of the assumptions and facts in those reports do not add up and I can figure that out in 30 seconds. I'm going to try and convince them to drop some of the more blatant stuff; this is probably the worst bit:
"There are eighteen regional trains that now terminate north of the Potomac River that could be extended to Lynchburg, Newport News, and Norfolk, providing more frequent service along these lines, or the routes of these trains could be extended further to serve additional destinations. This would enable the Commonwealth to increase regional service levels 400 percent without having to invest in costly train equipment."
I'm going to assume that the equipment being referred to is the passenger cars (since you'd definitely need more locomotives). Extending those trains into Hampton Roads and Lynchburg adds roughly 6-8 hours of travel time to those trains' routes. Some of those trains have to turn at WAS. Let's take trains 151 and 111 (arriving in WAS at 0815 and 0845, respectively). Those are going to go back north later in the day. Now extend 151 to Norfolk (3:05 each way) and 111 to Lynchburg (4:05 each way). Assuming that the trains are basically continuously in motion and only allowing an hour to get the trains turned around and back out of the station at their terminus (and half an hour for the "toaster pop" at Washington):
-151 leaves Washington at 0845. It arrives in Norfolk at 1150 (right about when 67 is scheduled to hit NPN). It turns around at 1250, and gets back to Washington at 1555. It is probably ready to go out of Washington by 1630.
-111 leaves Washington at 0915. It arrives in Lynchburg at 1320, turns around at 1420, and gets back to Washington at 1825.
It should be obvious that these times are optimistic, and that allowing 2-3 hours to clean and turn the sets kills the ability to actually get them back to DC in a timely manner to use them. So Amtrak (or Virginia) will have to come up with some equipment to supplement what is already there if they want to extend everything.
The other problem that I've raised is that simply extending the existing Regional timetable deep into VA is a formula for lots of really badly-timed trains. I can take 3-4 trains with late-night departures...what doesn't stand up is that, assuming they were fully extended, you'd probably have about 9 trains leaving their origin stations prior to 0530. Of these, only 190 (dep. WAS 0315) and 110 (dep. WAS 0400) are salvagable in my mind, for the simple fact that the departures back up into the previous evening. 170 (dep. WAS 0452) could perhaps be stretched there as well, but that leaves 180, 130, 172, 86, 184, and 174 leaving at times that range from passable to awful. Extending some makes sense but, as I expressed to a DRPT representative one time, there may be the business at Norfolk for an 0500 train. There probably is not the business to justify an 0400 train, an 0500 train, and an 0600 train with nothing else.
Another issue with this is the fact that if a bunch of these trains are running overnight, there probably needs to be a serious discussion about at least getting 2-1 BC cars on them, if not adding actually adding sleepers to some of them. It isn't as big a deal for a departure at 0400, but if you're looking at a departure at 2300 or 0100 you have another story to deal with.
A final thought does come out from that point: If VA is running wacky-hour trains down to Lynchburg, that's probably about the right time to put in a call to North Carolina and seriously discuss extending that train to Charlotte if it isn't going to Roanoke.
In the end, if VA wants to have the levels of service that VHSR is promoting, there probably needs to be a serious discussion with Amtrak about (A) Virginia acquiring a few sets of their own equipment and (B) serious efforts to time trains a bit better so the state isn't overly loaded with middle-of-the-night departures.
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As to the 90-minute time RVR-WAS, my understanding is that such a plan would be in the $1.8bn HSR proposal or thereabouts. A rough rundown would be here:
http://www.drpt.virginia.gov/studies/files/WashingtonDCStudyDetails.pdf
(Warning: The linked report is about 20 years old, so the costs...and probably the ridership estimates...are going to be questionable. Some of the projects have likely already happend; others would have been replaced by other projects as time has gone on.