The San Francisco Planning and Urban Research Association has put together a new exhibit that provides an overview of urban planning. See 10 of the diagrams and short descriptions here. Also, here is a quick overview of the exhibit:

The exhibition’s title – Grand Reductions – suggests the simple illustration’s power to encapsulate complex ideas. And for that reason the medium has always been suited to the city, an intricate organism that has been re-imagined (with satellite towns! in rural grids! in megaregions!) by generations of architects, planners and idealists. In the urban context, diagrams can be powerful precisely because they make weighty questions of land use and design digestible in a single sweep of the eye. But as Le Corbusier’s plan illustrates, they can also seductively oversimplify the problems of cities. These 10 diagrams have been tremendously influential – not always for the good.

“The diagram can cut both ways: It can either be a distillation in the best sense of really taking a very complex set of issues and providing us with a very elegant communication of the solution,” Grant says. “Or it can artificially simplify something that actually needs to be complex.”

Over the years, some of these drawings have perhaps been taken too literally, while others likely lie behind some of your favorite spots in your city. “Even if you don’t know the diagram,” Grant says, “you might know the places that the diagram inspired.” SPUR shared these images from the exhibition, which opened this week. If you happen to live in San Francisco, you can also visit the show in person at the SPUR Urban Center Gallery (654 Mission Street) through February (oh, and it’s free!).

Three things strike me when looking at these influential diagrams:

1. On one hand, these diagrams are very similar to maps. On the other hand, they involve a particular vision that can sometimes be hard to achieve with a two dimensional image. These diagrams provide particular perspectives but they go beyond just being maps because the creators (and perhaps some of the viewers) can see a bigger picture.

2. They indicate a more scientific or rational approach to putting together cities. Particularly in the last century, urban planning has become a professional field that involves theories along with specific training and methods. These diagrams involve a lot of straight lines, overhead views, and the idea that the proper placement of buildings, streets, and other features can lead to the right outcomes.

3. These diagrams are quite artistic. Do they qualify as art?