I didn't know this, but according to the New York freaking Times, Northfield is setting a national trend by severely restricting the construction of cul-de-sacs. Not only that, but the lead to this story in the Times' Real Estate section discusses a construction site that's literally around the corner from our place - we can hear the "dinosaur machines" (as Julia calls them) working all day.
Local pride notwithstanding, the article's also a good primer on the theory and practice of culs-de-sac (not "cul-de-sacs," NYT!) in contemporary urban design.