Coming soon all over Virginia: More of the bottom one.

One of the keystone rules of good urbanism is that interconnected streets are better than disconnected ones. Traditional blocks connected by a grid (or something like a grid) reduce congestion and improve safety by eliminating the bottlenecks inherent in the arterial-collector street system, which funnels all traffic in a given area onto just one or two roads. With a grid, you get options. The transportation eggs aren’t all in one basket.

Good on Virginia then for adopting new regulations requiring future subdivisions to include through streets linking them directly with other neighborhoods nearby. This is a relatively minor modification to long-standing VDOT regulations for new streets, but over time it’s going to make a huge difference to how development in Virginia works. It’s a bona fide statement by the government of the Commonwealth that the old arterial-collector system doesn’t work, and it’s time to move on.

Great news.

Update 3/26/09: Greater Greater Washington outlines the specifics of the new regulations.