Montgomery and Arlington counties have both been very good at turning their Metro stations into TODs. However, the pattern of how they developed in each jurisdiction varies due to the spacing of Metro stations.

In Arlington, stations are clustered close together in two corridors (Rosslyn-Ballston and Pentagon-Crystal City), so that the TOD areas within each corridor function like neighborhoods within the larger “city” of Arlington. In Montgomery, stations are spaced a mile or so apart, resulting in TOD areas that each function as the downtown for otherwise independent cities, each with its own hinterlands.

Because the TODs in Arlington are clustered together, while those in Montgomery are spaced apart, it’s difficult to get a sense of how they compare to each other. Just how big is Silver Spring, compared to Rosslyn or Ballston, for example?

I set out to answer that question with a series of maps. These maps compare the Rosslyn-Ballston corridor’s 5 Metro station TODs to Bethesda, Friendship Heights, and Silver Spring, all at the same scale. I left out Pentagon-Crystal City, Rockville, and Alexandria, although they might make good additions some time in the future.

First, a reference map. Using Google Maps set at the 2,000 foot view, I colored in the dense portions of each TOD, deleted the surroundings, then put them all on the same page. In this first map, Bethesda and Friendship Heights are shown at the proper distance from each other, in addition to being scaled by area.

Rotating the Wisconsin Avenue axis of Bethesda-Friendship Heights to match Rosslyn-Ballston, and then placing downtown Silver Spring between them, produces 2 almost identical corridors.

Overlaying Silver Spring and Bethesda atop Clarendon shows that if the Maryland TODs were part of Rosslyn-Ballston, they would each would stretch approximately from Court House to Virginia Square.