"What? And just where will these trains go? Franconia-Springfield to Greenbelt? Mt Vernon Sq? Will the Yellow Line even exist anymore?"
I took the liberty of ripping the text and tables from pages 44 and 45 from the PDF file this data comes from and posting them to the web. The last two tables show what lines get what number of trains and the number of car in each train.
"Then again, they could do it like this: Run trains from Largo to National Airport and from Greenbelt/Mt Vernon Sq. to Franconia-Springfield The idea is to make room for the trains from Tyson's Corner/Dulles Int'l Airport/Loudoun County. Does that mean to choke out the Yellow Line instead? Because I don't see any way for them to run from Largo to Franconia-Springfield using the Potomac River Bridge, and having half the Blue trains in the Yellow/Green segment... one of the three lines is going to get strangled by the other two."
From what I could see in the tables some thing under 50% of the trains dispatched out of Springfield-Francine (J03) will go to Greenbelt (E10). The remainder will go to Largo (G05). At present 20 trains are being run on the combined Green Yellow line By 2006 after Blue line reconfiguration 25 trains will be running from L’Enfant (F03) to points north.
On the other hand, they could build a flying junction that either bypasses L'Enfant Plaza, or goes through it, and then ducks out of the Blue/Orange tracks, and picks up the Yellow Line tracks. But, if they go through all that, they might as well just tunnel under the river, and connect at Pentagon or National Airport (they could do that, right? Or would they be forced to connect between National Airport and Braddock Road (probably near the Potomac Yard area))
There no need for such a schema. The reason is the Blue line east of Stadium-Armory (D08) has the lowest number of boarding of all the lines that reach in the suburbs.
As for scheduling of the trains on in the reconfiguration, we are going to have to wait and see as this is 3 years in the future and I don’t think the planners at WMATA have yet nailed that down yet.
John