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Since 1984, the nonprofit Island Press has been stimulating, shaping, and communicating the ideas that are essential for solving environmental problems worldwide. With more than 800 titles in print and some 40 new releases each year, we are the nation’s leading publisher on environmental issues. We identify innovative thinkers and emerging trends in the environmental field. We work with world-renowned experts and authors to develop cross-disciplinary solutions to environmental challenges.

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Measuring Urban Design

Metropolitan Planning + Design

Series editors: Arthur C. Nelson and Reid Ewing

A collaboration between Island Press and the University of Utah’s Department of City & Metropolitan Planning, this series provides a set of tools for students and professionals working to make our cities and metropolitan areas more sustainable, livable, prosperous, resilient, and equitable. As the world’s population grows to nine billion by mid-century, the population of the US will rise to one-half billion. Along the way, the physical landscape will be transformed. Indeed, two-thirds of the built environment in the US at mid-century will be constructed between now and then, presenting a monumental opportunity to reshape the places we live. The Metropolitan Planning + Design series presents an integrated approach to addressing this challenge, involving the fields of planning, architecture, landscape architecture, urban design, public policy, environmental studies, geography, and civil and environmental engineering. The series draws from the expertise of some of the world’s leading scholars in the field of Metropolitan Planning + Design.

Please see Islandpress.org/Utah/ for more information.

Other books in the series:

The TDR Handbook, Arthur C. Nelson, Rick Pruetz, and Doug Woodruff (2011)

Stewardship of the Built Environment, Robert Young (2012)

Governance and Equity, Marc Brenman and Thomas W. Sanchez (2012)

Good Urbanism: Six Steps to Creating Prosperous Places, Nan Ellin (2012)

Measuring Urban Design

Metrics for Livable Places

Reid Ewing & Otto Clemente

with

Kathryn M. Neckerman

Marnie Purciel-Hill

James W. Quinn

Andrew Rundle

Washington | Covelo | London

Copyright © 2013 Reid Ewing and Otto Clemente

All rights reserved under International and Pan-American Copyright Conventions. No part of this book may be reproduced in any form or by any means without permission in writing from the publisher: Island Press, 2000 M St. NW Suite 650, Washington, DC 20036

ISLAND PRESS is a trademark of The Center for Resource Economics.

Library of Congress Cataloging-in-Publication Data

Ewing, Reid H.

Measuring urban design : metrics for livable places / Reid Ewing and Otto Clemente with Kathryn M. Neckerman, Marnie Purciel-Hill, James W. Quinn, Andrew Rundle.

pages cm

Summary: What makes strolling down a particular street enjoyable? The authors of Measuring Urban Design argue it’s not an idle question. Inviting streets are the centerpiece of thriving, sustainable communities, but it can be difficult to pinpoint the precise design elements that make an area appealing. This accessible guide removes the mystery, providing clear methods to assess urban design. The book provides operational definitions and measurement protocols of five intangible qualities of urban design, specifically: imageability, visual enclosure, human scale, transparency, and complexity. The result is a reliable field survey instrument grounded in constructs from architecture, urban design, and planning. Readers will also find illustrated, step-by-step instructions to use the instrument and a scoring sheet for easy calculation of urban design quality scores--Provided by publisher.

Includes bibliographical references and index.

ISBN-13: 978-1-61091-193-1 (hardback)

ISBN-10: 1-61091-193-8 (cloth)

ISBN-13: 978-1-61091-194-8 (paper)

1. City planning--Social aspects. 2. Architecture--Human factors. 3. City planning--Methodology. I. Clemente, Otto. II. Title.

NA9053.H76E95 2013

711’.4—dc23

Printed on recycled, acid-free paper

Manufactured in the United States of America

10 9 8 7 6 5 4 3 2 1

Key Words: Columbia’s Built Environment and Health (BEH) group, complexity, human scale, D variables, imageability, Maryland Inventory of Urban Design Qualities (MIUDQ) protocol, legibility, linkage, perceptual qualities, Robert Wood Johnson Active Living Research (ALR), sidewalk connection, tidiness, transparency, visual enclosure, visual preference survey

Contents

Acknowledgments

ONE Introduction

Why You Should Read This Book

Initial Screening of Qualities

Map of the Book

TWO Data Collection

Expert Panel

Videotaping

Library of Video Clips and Sample

Visual Assessment Survey

THREE Analysis and Final Steps

Walkability in Relation to Urban Design Qualities

Inter-Rater Reliability of Scene Ratings

Analyzing the Content of Sampled Scenes

Inter-Rater Reliability of Content Analysis

Urban Design Ratings in Relation to Physical Features

Cross-Classified Random Effects Models

Results of Statistical Analysis

Final Steps

FOUR Urban Design Qualities for New York City

Kathryn M. Neckerman, Marnie Purciel-Hill, James W. Quinn, and Andrew Rundle

Background

Neighborhood Characteristics and Urban Design

Methods

Results

New Strategies for Measuring Urban Design

Conclusions

FIVE Validation of Measures

Data

Measures

D Variables

Analysis

Results

Discussion

SIX Field Manual

Getting Started

Urban Design Quality Definitions

Measurement Instructions

Appendix 1: Biosketches of Expert Panel Members

Appendix 2: Operational Definitions of Physical Features

Appendix 3: Urban Design Qualities and Physical Features

Appendix 4: Scoring Sheet Measuring Urban Design Qualities

References

Acknowledgments

This book is the result of an interdisciplinary, inter-university collaboration. Susan Handy, a professor of environmental policy at UC Davis, and Ross Brownson, an epidemiologist at Washington University in St. Louis, were full partners in the original study funded under the Robert Wood Johnson’s Active Living Research Program, Round 1, Identifying and Measuring Environmental Determinants of Physical Activity (grant # 50337). Susan is a leading researcher on the relationship between land use and travel. She has done seminal research on the factors that affect walking. Ross is regarded as one of the leaders in the field of evidence-based public health. He co-directs the Prevention Research Center in St. Louis—a major, CDC funded center jointly led by Washington University and Saint Louis University. Susan and I co-authored the article upon which Chapter 1 is based: Measuring the Unmeasurable: Measuring the Unmeasurable: Urban Design Qualities Related to Walkability. Ross and Susan participated in all phases of the ALR project as described in Chapters 2 and 3.

Additional collaborators include Kathy Neckerman and Andrew Rundle’s team at Columbia University, whose research is described in Chapter 4. They too were funded under the Active Living Research Program of the Robert Wood Johnson Foundation (grant #58089). Kathy is a sociologist at the Columbia Population Research Center and Andrew is an epidemiologist at Columbia’s Mailman School of Public Health. They co-direct the Built Environment and Health (BEH) research group at Columbia and have written extensively about disparities in neighborhood conditions and their implications for health and wellbeing.

The validation exercise in Chapter 5 involved several students and staff at the University of Utah: Mark Connors, Amir Hajrasouliha, Shima Hamidi, and J.P. Goates. J.P. generated GIS measures for buffers around the 588 sampled street segments in New York City. Mark, Amir, and Shima counted pedestrians in street-level imagery and comparing these counts to the manual counts.

The team at Island Press who took this book to publication includes senior editor Heather Boyer, associate editor Courtney Lix, and senior production editor Sharis Simonian. Their professionalism is evident in the final product. To all of the above, we say thanks.

Reid Ewing and Otto Clemente

CHAPTER ONE

Introduction

¹

In terms of the public realm, no element is more important than streets. This is where active travel to work, shop, eat out, and engage in other daily activities takes place, and where walking for exercise mostly occurs. Parks, plazas, trails, and other public places also have an important role in physical activity, but given the critical role and ubiquity of streets, this book focuses on the qualities that make one street more inviting and walkable than another. Think of your last trip to a great European city and what, other than the historic structures and the food, was memorable. You walked its streets for hours and did not tire. It is the magic of a great street environment.

Until recently, the measures used to characterize the built environment have been mostly gross qualities such as neighborhood density and street connectivity (see reviews by Ewing and Cervero 2010; Handy 2005; and Ewing 2005). The urban design literature points to subtler qualities that may influence choices about active travel and active leisure time. Referred to as perceptual qualities of the urban environment, or urban design qualities, such qualities are presumed to intervene between physical features and behavior, encouraging people to walk (see figure 1.1). Testing this presumption requires reliable methods of measuring urban design qualities, allowing comparison of these qualities to walking behavior.

Many tools for measuring the quality of the walking environment have emerged in the past few years. Generically called walking audit instruments, these are now used across the United States by researchers, local governments, and community groups. Robert Wood Johnson’s Active Living Research (ALR) website alone hosts sixteen walking audit instruments. They involve the measurement of such physical features as building height, block length, and street and sidewalk width.

Figure 1.1.

Urban design qualities are more than the individual physical features that they comprise, as they have a cumulative effect that is greater than the sum of the parts. Physical features individually may not tell us much about the experience of walking down a particular street. Specifically, they do not capture people’s overall perceptions of the street environment, perceptions that may have complex or subtle relationships to physical features.

Perceptual qualities are also different from such qualities as sense of comfort, sense of safety, and level of interest, which reflect how an individual reacts to a place—how a person assesses the conditions there, given his or her own attitudes and preferences. Perceptions are just that—perceptions. They may elicit different reactions in different people. They can be assessed objectively by outside observers; individual reactions cannot.

Our challenge in creating a tool to measure urban design qualities was to move from highly subjective definitions to operational definitions that capture the essence of each quality and can be measured reliably across raters, including those without training in urban design.

Why You Should Read This Book

Measuring Urban Design provides operational definitions and measurement protocols for five intangible qualities of urban design: imageability, visual enclosure, human scale, transparency, and complexity. To help disseminate these measures, this book also provides a field survey instrument that has been tested and refined for use by lay observers.

This instrument has several strengths. First, it is grounded conceptually in constructs from architecture, urban design, and planning. Second, it has been carefully tested and validated. Third, it comes with detailed instructions for assessing the five urban design qualities. For these reasons, the instrument offers researchers a gold standard for the systematic measurement of urban design. A test in New York City showed that the instrument can be implemented in large-scale studies relating the built environment to social, psychological, and health outcomes.

Initial Screening of Qualities

Key perceptual qualities of the urban environment were identified based on a review of the classic urban design literature. Without much empirical evidence, these qualities are presumed to influence people’s decisions to walk rather than drive to a destination, stroll in their leisure time, or just hang out and socialize on a street. Perceptual qualities figure prominently in such classics as those listed in box 1.1.

The research team also reviewed the visual preference and assessment literatures, which attempt to measure how individuals perceive their environments and to better understand what individuals value in their environments. Partial listing of this voluminous empirical literature is provided in Ewing (2000) and updated in Ewing et al. (2005). These literature reviews go beyond the boundaries of urban design to the fields of architecture, landscape architecture, park planning, and environmental psychology, as perceptual qualities of the environment figure prominently in these fields as well.

Our review yielded a list of fifty-one perceptual qualities of the urban environment (box 1.2). Of these fifty-one qualities, eight were selected for further study based on the importance assigned to them in the literature: imageability, enclosure, human scale, transparency, complexity, coherence, legibility, and linkage. Of the eight, the first five were successfully measured in a manner that passed tests of validity and reliability.

Box 1.1.

Classic Works in Urban Design That Address Perceptual Qualities

City Planning according to Artistic Principles, Camillo Sitte, 1889 (complete English translation 1986)

The Image of the City, Kevin Lynch, 1960

The Concise Townscape, Gordon Cullen, 1961

The Death and Life of Great American Cities, Jane Jacobs, 1961

A Pattern Language: Towns, Buildings, Construction, Christopher Alexander, Sara Ishikawa, and Murray Silverstein, 1977

Fundamentals of Urban Design, Richard Hedman, 1984

Finding Lost Space: Theories of Urban Design, Roger Trancik, 1986

Life between Buildings: Using Public Space, Jan Gehl, 1987

City: Rediscovering the Center, William Whyte, 1988

Town Planning in Practice, Raymond Unwin, 1909

History and Precedent in Environmental Design, Amos Rapoport, 1990

Great Streets, Allan Jacobs, 1993

Trees in Urban Design, Henry Arnold, 1993

Box 1.2.

Fifty-One Perceptual Qualities of the Built Environment

adaptability

distinctiveness

intricacy

richness

ambiguity

diversity

legibility

sensuousness

centrality

dominance

linkage

singularity

clarity

enclosure

meaning

spaciousness

coherence

expectancy

mystery

territoriality

comfort

focality

naturalness

texture

compatibility

formality

novelty

transparency

complementarity

human scale

openness

unity

complexity

identifiability

ornateness

upkeep

continuity

imageability

prospect

variety

contrast

intelligibility

refuge

visibility

deflection

interest

regularity

vividness

depth

intimacy

rhythm

Imageability

Imageability is the quality of a place that makes it distinct, recognizable, and memorable.