Urban access across the globe: an international comparison of different transport modes

Hao Wu,John P Pritchard,Paolo Avner,Michał A Niedzielski,Brendan Murphy,David Levinson,Genevieve Boisjoly,Ahmed El-Geneidy,Jiaoe Wang,Jie Huang,Carlos K V Braga,Tamara Kerzhner,Anson Stewart,Rafael H M Pereira

doi:10.1038/s42949-021-00020-2

Abstract

Access (the ease of reaching valued destinations) is underpinned by land use and transport infrastructure. The importance of access in transport, sustainability, and urban economics is increasingly recognized. In particular, access provides a universal unit of measurement to examine cities for the efficiency of transport and land-use systems. This paper examines the relationship between population-weighted access and metropolitan population in global metropolitan areas (cities) using 30-min cumulative access to jobs for 4 different modes of transport; 117 cities from 16 countries and 6 continents are included. Sprawling development with the intensive road network in American cities produces modest automobile access relative to their sizes, but American cities lag behind globally in transit and walking access; Australian and Canadian cities have lower automobile access, but better transit access than American cities; combining compact development with an intensive network produces the highest access in Chinese and European cities for their sizes. Hence density and mobility co-produce better access. This paper finds access to jobs increases with populations sublinearly, so doubling the metropolitan population results in less than double access to jobs. The relationship between population and access characterizes regions, countries, and cities, and significant similarities exist between cities from the same country.

Highlights

Cities exist to enable people to reach other people, goods, and services
This paper measures how access varies with metropolitan population size, whether larger cities enjoy increasing accessibility, which we expect will affect how well population produces economies of agglomeration
In order to compare accessibility across cities worldwide, we first compare the relationship between the population size and accessibility in different countries. Such comparison can help clarify the differences in the relationship, and in the returns to scale of metropolitan population size on accessibility between different countries, i.e., is the increase in access proportional to the increase in population in each country, and how different countries compare

Summary

Introduction

Cities exist to enable people to reach other people, goods, and services. This is achieved through transport networks, which move people across space faster, and land-use patterns, which distribute people, goods, and services across space. Access (or “accessibility”) is the ease of reaching those valued destinations, and is a critical measure of urban efficiency. Higher land use density and travel speeds correspond with greater access[1]. Urban population size has been associated with greater productivity and creativity, a centerpiece of the urban economies of agglomeration literature[2,3]. This paper measures how access varies with metropolitan population size, whether larger cities enjoy increasing accessibility, which we expect will affect how well population produces economies of agglomeration

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