The Capital Beltway
(I-495) is in the upper left of the picture, and is most visible crossing
the Potomac River; the George Washington Memorial Parkway is the major road running along
the Virginia side. River Road runs diagonally through the upper right corner, and
a small portion of DC is visible in the lower right. 
Depending on your browser, screen resolution and stuff, the words in this paragraph might even line up with the blob and line indicating roughly where I live. Not likely, though.