Take a look at the following. This stuff blows my mind:

http://sphere.math.utsa.edu/sphere/salingar/urbanstructure.html

Basically, mathematician and urban studies scholar Nikos

Salingaros has drawn the outlines of a mathematical study

of human ecology, starting principally with urban planning

(but the applications extend well beyond, as he hints in

various places).

The basic impression I get from what he is saying is that,

as the power and resources at the disposal of centralized

corporate and government bureaucracies grows, so, too,

does their ability to impose top-down designs that, for

whatever aesthetic or useful purposes they may be intended

to fulfill in the minds of the planners, systematically

violate the design patterns that arise and are inherent in

any spontaneously emergent complex natural system (e.g.,

a human urban environment predating modern planning).

He presents a strong case that there are certain very

regular properties, analogous to those found in fractal

geometries, that characterize natural systems. One of

them is "self-similarity" over a large range of scales. To

put things simply, in natural and spontaneously emergent

complex systems, the relative numbers of objects at any

particular scale are in some constant inverse proportion to

the area they take up. He states this as the "hyperbolic

multiplicity rule," px^m = C, where p is the relative

number of objects of a particular scale, and x is the

scale (say, for instance, a width in feet), and m is the

"dimension" (a number usually between 1 and 2).

These abstract mathematical patterns are objectively

related to aesthetics. Human beings find their

surroundings less interesting and engaging when their

properties deviate excessively from these patterns. This is

easy to see in the extreme cases, for example: a uniform

distribution of massive, featureless objects produces

monotony (outsized px^m), whereas a distribution of objects

totally random over all scales produces an impression of

chaos. These impressions are in turn produced by definite

properties of human cognition. To quote Salinngaros:

"Scales play a major, even if subconscious, role in design

because they facilitate the process of human cognition. The

mind of the observer groups similar objects of the same

size into a single level of scale. This process, which has

been compared with digital image compression in computers,

reduces the amount of information presented to the observer

by a complex structure. The mind apparently also estimates

the number of similar objects on each scale, i.e., their

relative multiplicity, and compares these numbers to what

it knows regarding complexity from naturally occurring

structures. If the distribution of scales and the relative

multiplicity of elements correspond to an experientially

generated internal standard, we perceive the structure

as coherent."

Contrary to the complaint often voiced by well-intentioned

people, it makes me think that "planning" as such is more

the problem than the solution. It would be all too easy

for any well intentioned planner to try to optimize a

network for some particular utilitarian property, such as

distance from any particular service (or, as is so often

the case, speed and volume of auto traffic, for instance),

only to produce a network that was highly dysfunctional

for other reasons. When many people spontaneously organize

themselves into cities, they build settlements in patterns

that simultaneously balance a large number of factors. When

large corporations or governments build settlements for

them, the results are bound to produce terrible pathologies

which would never occur naturally. If we are stuck for

now with such institutions, perhaps the best we can do

is to at least avoid the worst sorts of mistakes, such as

the violent disfiguration of "geometrical fundamentalism"

imposed by modernist urban planning (see, for example,

http://www.plannet.com/features/geometricalfundamentalism.html).