Yesterday, Apple Computer announced a slew of new products, among them iTunes 7. A key feature of this piece of software is its new user interface, dubbed "CoverFlow", discussed in this article: Wired News: New UI Showdown: Apple vs. TiVo. You do need to see it to fully understand it, and it is quite a slick way to navigate a music database.
Why am I talking about music databases and album art in a blog about transportation? I think cities are much like databases, and buildings like album covers. We navigate spatially and visually. Cities without redeeming art, architecture or natural landmarks are unpleasant. Not merely because they lack "charm" and the buildings are individually dull, but because of their collective undifferentiatedness, which creates difficulties for navigating (especially if they also lack some spatial regularity like a comprehensible grid network) and spatially locating oneself. Being lost (both not knowing where you are and not knowing either how you got there or how you will get to where you are going) brings a strong sense of unease that creates frustration if not hostility to the place you are lost at.
Cities need the equivalent of album art so that people can explore them. The nature of this art changes if you are walking, biking, taking transit, or driving, as you view it at different speeds and different resolutions.
Skylines have value, more than the simple value to the owner of the individual building. (In economic terms, they provide some positive externality, collectively exhibiting a network effect where the whole is larger than the sum of the individual parts. Measuring this is of course difficult.)
When I am driving around, and see the skyline in the distance from a particular angle, I instantly know what direction I am going. While some of these benefits may be obviated with in-vehicle navigation, the certainty of physical structure outweighs the digital outputs of a machine.
I recall as a freshman at Georgia Tech, taking a night course, leaving some classroom building for the first time out of a door different from where I entered and being completely turned around, until eventually I located the Coca-Cola headquarters building (just southwest of campus). While I still didn't know exactly where I was, I could figure out where I was going.