Skip to Content
Streetsblog New York City home
Streetsblog New York City home
Log In
Streetsblog

How Grid Systems Promote Urbanism and Winding Streets Undermine It

11:40 AM EDT on August 23, 2012

false

What's the difference between a sleepy, sprawling place and a vibrant, compact one? According to a fascinating theory from Patrick Kennedy at Network blog Walkable Dallas Fort Worth, the primary factor is the street pattern.

Street grids, he asserts, exert a centripetal force on the market, drawing investment toward the core. Meanwhile, suburban-style streets -- a "dendritic," or branch-like, pattern -- spread land value evenly, and impart an outward tug.

It's all related to the question of connectedness, and the value that's attached to that, Kennedy says:

The transpo network, the connectivity, is the first order system applied to a place. The "body," or the physical city of uses and buildings, is the emergent second order network that is entirely dependent upon the degree of connectivity at the order below.

The rigidly hierarchical dendritic pattern is indicative of a flat or spread out "market." No place is really any more or less interconnected than other places (thus why studies like intersection density and space syntax are valuable -- they measure interconnectedness). In cities, the degree to which you are connected to persons, places, and things determines the value of that particular site. The higher the value, the greater the demand, opportunity, and therefore density. Because the hierarchical 1st order system produces little hierarchy in the 2nd order system, it suggests an outward or centrifugal force, or outward pressure, on the real estate market. All places are equitable. Evenly and poorly interconnected. And the result is sprawl. Demand smeared evenly across the entire landscape.

Because the hierarchy inherent in reticulated systems only appears at the next level of complexity and order, it can be said that reticulated grids exert centripetal force on the real estate market or convergent. There is greater value at intersections and hubs of networks because they are more interconnected. How we value the availability and amount of the possible interconnections between people, places, and things drives city form by driving demand, and in turn density -- inward.

Kennedy concludes that traditional transportation modeling fails to take these factors into account. The proper way for cities to mature, and to accommodate traffic, is to let the grid system absorb growth, he says. Anything else is "wholly irrational, unnatural, and illogical, broken, anti-city."

Elsewhere on the Network today: The Get Around Blog takes on Chicago Tribune columnist John Kass's bizarre assertion recently that cyclists should be assessed in a complicated system of user fees. Systemic Failure explains that drivers under the influence of the prescription drug Ambien have been responsible for some horrifying injuries behind the wheel of cars, but have been able to use the drug's effects as defense against criminal charges. And Market Urbanism says that Ayn Rand's writings on cities don't really align with her choice of where to live.

Stay in touch

Sign up for our free newsletter

More from Streetsblog New York City

Con Edison Cons Its Way Out of Paying Traffic Tickets

The massive energy company is bilking the city of tens of thousands of dollars in potential camera-issued traffic violations by obscuring its trucks’ license plates.

March 1, 2024

West Side Glory: State Begins the Process of Reimagining a True NYC Car Sewer

The state DOT will study the West Side Highway for "potential enhancements ... including [for] pedestrians and cyclists." West Side officials are cheering!

March 1, 2024

Friday’s Headlines: Closing the Bike Share Black Hole Edition

Council Member Lincoln Restler has negotiated with local religious leaders to add Citi Bike docks to south Williamsburg. Plus other news.

March 1, 2024

Manhattan Pol Upset at Delayed Rollout of Electrified Citi Bike Docks

"I urge the Department of Transportation and Con Edison to expedite the electrification of [Citi Bike] stations," Erik Bottcher wrote to the colossuses of conveyance and current last Friday.

February 29, 2024
See all posts