We're several weeks away from Metro announcing more details about this summer's OL shutdown for the PiP, including what bus bridges will exist. I thought that might be an interesting point for folks to weigh in on here.
Based on what Metro did last summer with Huntington and Franconia-Springfield, and also looking at a map, I assume the 'express' buses would be staged at Vienna station, which seems well-equipped to handle a large fleet of couch-style buses. It also has easy access to I-66 in both directions. What I cannot decide is where those express buses will be heading - Ballston? Somewhere further towards DC? Last year, Metro really got lucky because Pentagon was open and has a massive bus depot. I am not sure if any stations on the OL from Ballston onward are anywhere near that conducive to a large-scale bus bridge.
As for the 'local' buses, Metro could use the following route: from Vienna station, take Lee Hwy to Gallows Rd to service Dunn Loring. Then, continue north on Gallows Rd to Idylwood Rd, which I recognize is not an especially high-capacity road. But, it would seem to provide easy access to WFC via Great Falls St. and then Haycock Rd. Anyone more familiar with this area may have a better route from Dunn Loring to WFC. From WFC to EFC, it seems there are several possible routes using both major and minor roads. For instance, from WFC the buses could go Haycock Rd to Rt 7, then N. West St to Lincoln Ave to Fairfax Dr to Wash Blvd. Or, alternatively, just Haycock to Rt 7 to Rt 29 to Wash Blvd. Finally, I'd make Ballston the end point for the local buses, so you could route them along Washington Blvd all the way from EFC to Ballston, using Glebe to get to Fairfax Dr.
I realize that the local buses could also at times jump on/off highway, too. I also am not familiar with existing bus routes in this area, so Metro may already have workable routes the mimic the OL in this area.
Living in Springfield, VA; Working at Half & L, DC.