It seems somewhat excessive to me too, but I think that the idea is to redevelop most of that area at a higher density than currently exists, much like Arlington County did along the Orange Line. For example, when the Virginia Square station first opened there was almost no reason for anyone to use it as there was very little in the immediate area, but now it has dense development all around it.
George Mason University law school, FDIC, and DARPA now are all in one block of Virginia Square exit. A 19-story apartment building sits atop it, with four other 8- to 20-story apartment/condo buildings within two blocks. Most, if not all, of these residences were built since 2000. There's no lack of Metro riders. And racks for 20 of those red "rent-a-bikes" were installed here this week.
Clarendon, next station east of VA Square-GMU, has just had major redevelopment of high-rise apartments and condos, at least two just completed within the 6 to 8 months. Plus major office buildings.
Ballston, next station west of VA Square-GMU station, is full of even taller high-rises, with an urban mall about two blocks away. It has a completely urban look at the Metro stop. Besides, a lot of Metro buses feed riders into the system at Ballston, so that station is always crowded.
As the crow flies, it is less than a mile from Ballston to Clarendon.
After picking up commuters at these three stations, it's pretty much "Orange Crush" into DC every workday.
Seeing this in Arlington, I have to agree with Davy's insight. Considering the already existing growth around Tyson's Corner, I'd expect those close-together stations will generate even further growth and still more need for public transit to alleviate road traffic. Building the stations now may be costly, but acquiring the facilities
after added development would be even costlier, especially if there is a need for extra land for bus transfer points and parking lots.
