Last night, "Rock Center with Brian Williams" featured this 2:25 minute discussion by Harry Smith with New York City's Transportation Commissioner Janette Sadik-Khan on the closing of streets in Times Square and elsewhere in the city.
Although Reston doesn't have the same congestion as Manhattan, there still might be a lesson in this video for closing some of Reston's most urbanized streets, such as Market Street from Presidents Drive to St. Francis St. This would not impede residents in the area, but yet would offer pedestrians and bicyclists unimpeded access to the office buildings and retail in the area. That Reston Town Center already closes Market Street for special events shows the value of this approach on a more general scale. As density grows in Town Center and the other two Reston TOD areas, maybe parts of the the new "grid of streets" could be walking boulevards instead of roads.