I didn't manage to get out and check out various Park(ing) Day installations across the city and metropolitan area. Washington Business Journal has a gallery of photos and a short article.
Parking Day started in 2005 in San Francisco and sparked the parklet movement, which has become institutionalized in many communities. The idea was to challenge our taking it for granted thinking about how cities use a majority of their public space for car storage. Park(ing) Day is held the third Friday of September.
I still think that such installations could be better used to promote systematic structural improvements in urban public space and civic design and parks policy and practice, but that will have to wait til sometime in the future.
-- news coverage from around the country
Image from the Gray Matters blog at Georgia Tech, 2011.