A typology of street patterns

TL;DR

This paper introduces a quantitative method to classify and compare city street patterns using shape factor distributions, revealing regional differences and internal city diversity.

Contribution

It presents a novel fingerprint-based typology of cities based on street block shape and size distributions, applied to 131 cities worldwide.

Findings

Identified four major city families with distinct block characteristics.

European and American cities form separate sub-categories.

City fingerprints can be decomposed into neighborhood fingerprints.

Abstract

We propose a quantitative method to classify cities according to their street pattern. We use the conditional probability distribution of shape factor of blocks with a given area, and define what could constitute the `fingerprint' of a city. Using a simple hierarchical clustering method, these fingerprints can then serve as a basis for a typology of cities. We apply this method to a set of 131 cities in the world, and at an intermediate level of the dendrogram, we observe 4 large families of cities characterized by different abundances of blocks of a certain area and shape. At a lower level of the classification, we find that most European cities and American cities in our sample fall in their own sub-category, highlighting quantitatively the differences between the typical layouts of cities in both regions. We also show with the example of New York and its different Boroughs, that the fingerprint of a city can be seen as the sum of the ones characterising the different neighbourhoods inside a city. This method provides a quantitative comparison of urban street patterns, which could be helpful for a better understanding of the causes and mechanisms behind their distinct shapes.