Actually guys, I did a bit of sleuthing on my own, and judging from its postition to the Capital Beltway and the nearby town of Wheaton, I've concluded that it's http://maps.google.com.au/maps?q=beltsville&oe=utf-8&rls=org.mozilla:en-GB:official&client=firefox-a&um=1&ie=UTF-8&hq=&hnear=Beltsville,+MD,+USA&gl=au&ei=t9S5Te-jAo_CvQPh8rS-Cw&sa=X&oi=geocode_result&ct=title&resnum=1&ved=0CCkQ8gEwAA.
Which means that Canterbury Commons, which is just a little further north,
could be either the town of Laurel or Maryland City.
But yeah. New Vegas seems to be a bit more accurate in regards to where places are. Fallout 3 on the other hand? Nearly impossible to figure out!