Categories
Planning

Resilient by Design

I have a new article out now in Transportation Research Part A: Policy and Practice. Here’s a free open-access preprint if you lack institutional access.

We simulate over 2.4 billion trips across every urban area in the world to measure street network vulnerability to disasters, then measure the relationships between street network design and these vulnerability indicators.

First we modeled the street networks of more than 8,000 urban areas in 178 countries. Then, for each urban area, we simulated disasters of 3 different types (representing floods, earthquakes, and targeted attacks) and 10 different extents. Then we simulated over 2.4 billion trips on these networks to measure how certain trips become more circuitous or even impossible to complete as parts of the network fail after a disaster. Finally we built a model to predict how much a disaster would impact trips.

Categories
Urban

Equity in the Built Environment

I coauthored a recently published article in Building and Environment which systematically reviews perspectives on and approaches to social equity in the built environment. From the abstract:

Equity in the built environment refers to the extent to which the built environment meets the needs of different groups through planning, design, construction, operation, management, and regulation. Though much studied in recent years, some needs and groups have received a greater research focus than others, and significant inequities continue to exist. Following PRISMA guidelines, we systematically reviewed the distributional and recognitional aspects of inequities experienced by vulnerable groups regarding their needs while using/occupying different types of built environments. We find that more studies focus on inequities regarding residential buildings, transportation facilities, and public open spaces, whereas comparatively few studies examine water and energy infrastructure, commercial buildings, educational buildings, and healthcare facilities. More studies focus on well-being, mobility, and access needs than shelter and safety needs. Inequities experienced by minorities, people with low socioeconomic status, people with health concerns, and vulnerable age groups receive more attention than the inequities experienced by people with gender/sexual-orientation vulnerability or displaced groups. The literature exhibits a relatively narrow focus on some subgroups, such as refugees, people experiencing homelessness, people with cognitive differences, people with visual or hearing impairments, children, and women. We argue that these findings demarcate high-impact future research directions to address vulnerable groups’ needs worldwide and suggest measures to alleviate inequities in the built environment.

For more, check out the article itself in Building and Environment.

Categories
Planning

Air Pollution Exposure in Los Angeles

I have a new article out now in Urban Studies, which finds that—all else equal—residents of Los Angeles census tracts that generate more vehicular travel tend to be exposed to less vehicular air pollution, and that tracts with a larger non-white population proportion—whether high- or low-income—experience more air pollution than do whiter but otherwise similar tracts. There’s also a free, open access pre-print available.

Twentieth century planners designed and constructed an enormous network of expressways to open up growing American metropolises to motorists. Vast swaths of established urban neighborhoods were bulldozed to clear new channels for suburban residents to drive to job centers. Yet some older neighborhoods survived relatively unscathed.

For example, in Los Angeles, local residents organized to protest and eventually successfully cancel plans to extend State Route 2 through the affluent communities of Beverly Hills and Los Angeles’s westside. In contrast, similar grassroots efforts failed in Los Angeles’s eastside, where several major freeways carved up its less-affluent and less-white neighborhoods.

Categories
Planning

Delivering Healthy and Sustainable Cities

I have a new article out now in The Journal of City Climate Policy and Economy, coauthored with a team that includes several of the folks from our recent series in The Lancet Global Health. The JCCPE article, “A Pathway to Prioritizing and Delivering Healthy and Sustainable Cities,” synthesizes findings and recommended policy actions arising from that recent TLGH series.

From the abstract:

Creating healthy and sustainable cities should be a global priority. Some cities prioritize 15-minute cities as a planning approach with co-benefits for health, climate change mitigation, equity, and economic recovery from COVID-19. Yet, as our recent The Lancet Global Health series on “Urban Design, Transport, and Health” showed, many cities have a long way to go to achieve this vision. This policy guideline summarizes the main findings of the series, which assessed health and sustainability indicators for 25 cities in 19 countries. We then outline steps governments can take to strengthen policy frameworks and deliver more healthy, equitable, and sustainable built environments. The Lancet Global Health series provided clear evidence that cities need to transform urban governance to enable integrated planning for health and sustainability and commit to policy implementation. Evidence-informed indicators should be used to benchmark and monitor progress. Cities need policy frameworks that are comprehensive and consistent with evidence, with measurable policy targets to support implementation and accountability. The series provided evidence-informed thresholds for some key urban design and transport features, which can be embedded as policy targets. Policies and interventions must prioritize identifying and reducing inequities in access to health-supportive environments. Governments should also invest in open data and promote citizen-science programmes, to support indicator development and research for public benefit. We provide tools to replicate our indicators and an invitation to join our 1,000 Cities Challenge via the Global Observatory of Healthy and Sustainable Cities.

For more, check out the JCCPE article itself. And you may also be interested in our recent The Lancet Global Health series of articles that developed similar themes in great depth.

Categories
Planning

ISPAH in Abu Dhabi

Alongside Billie Giles-Corti and Jim Sallis, I will be presenting our team’s recent research into accessible, sustainable urban design around the world at the ISPAH Congress in Abu Dhabi this week. Our symposium at the congress will share the methods and findings from our The Lancet Global Health series published this summer, as well as our ongoing work on the Thousand Cities Challenge.

Our geospatial team developed open-source software to calculate indicators of walkability and accessibility around the world, and then linked these back to cities’ policy contexts and identified populations living above and below estimated thresholds for physical activity. Few cities had measurable policy standards and targets to actually build healthier and more sustainable cities, and their health-supportive built environment features were often inadequate or inequitably distributed.

We simultaneously launched the Global Observatory of Healthy and Sustainable Cities to promote healthy and sustainable urban planning, benchmark and monitor cities’ progress, and share more consistent, comparable urban data. The whole series of articles is free and open access, as is our software.

Categories
Urban

Scaling Urban Indicators

I have a new article out now in the journal of Urban Policy and Research coauthored with a team comprising many of the folks from our recent series in The Lancet Global Health. The article is titled “Policy-Relevant Spatial Indicators of Urban Liveability and Sustainability: Scaling from Local to Global” and discusses measuring urban indicators and scaling the software to calculate them from a local case study to a worldwide effort.

From the abstract:

Urban liveability is a global priority for creating healthy, sustainable cities. Measurement of policy-relevant spatial indicators of the built and natural environment supports city planning at all levels of government. Analysis of their spatial distribution within cities, and impacts on individuals and communities, is crucial to ensure planning decisions are effective and equitable. This paper outlines challenges and lessons from a 5-year collaborative research program, scaling up a software workflow for calculating a composite indicator of urban liveability for residential address points across Melbourne, to Australia’s 21 largest cities, and further extension to 25 global cities in diverse contexts.

For more, check out the article itself. And you may also be interested in our recent The Lancet Global Health series of articles that developed similar themes in great depth.

Categories
Urban

The Lancet Global Health Series on Urban Design, Transport, and Health

After many years of hard work, our series of articles on urban design, transport, and health has been published by The Lancet Global Health.

The Lancet Global Health infographic on benchmarking healthy sustainable citiesIn our first paper, we analyzed urban policies and calculated built environment indicators for 25 cities across 6 continents to assess walkability and accessibility. Our policy analysis found policies inconsistent with public health evidence, rhetoric endorsing health and sustainability but few measurable policy targets, and substantial implementation gaps.

Categories
Planning

Framework for Measuring Pedestrian Accessibility

I’m a co-author of a new article, “A Generalized Framework for Measuring Pedestrian Accessibility around the World Using Open Data,” which has just been published by Geographical Analysis. We developed an open source, containerized software framework for modeling pedestrian networks using open data to analyze disaggregate access to daily living needs. We worked with local partners in 25 cities around the world to demonstrate and validate this toolkit.

From the abstract:

Pedestrian accessibility is an important factor in urban transport and land use policy and critical for creating healthy, sustainable cities. Developing and evaluating indicators measuring inequalities in pedestrian accessibility can help planners and policymakers benchmark and monitor the progress of city planning interventions. However, measuring and assessing indicators of urban design and transport features at high resolution worldwide to enable city comparisons is challenging due to limited availability of official, high quality, and comparable spatial data, as well as spatial analysis tools offering customizable frameworks for indicator construction and analysis. To address these challenges, this study develops an open source software framework to construct pedestrian accessibility indicators for cities using open and consistent data. It presents a generalized method to consistently measure pedestrian accessibility at high resolution and spatially aggregated scale, to allow for both within- and between-city analyses. The open source and open data methods developed in this study can be extended to other cities worldwide to support local planning and policymaking. The software is made publicly available for reuse in an open repository.

For more, check out the article.

Categories
Urban

Urban Form and OpenStreetMap

My chapter “Exploring Urban Form Through OpenStreetMap Data: A Visual Introduction” has just been published in the new book Urban Experience and Design: Contemporary Perspectives on Improving the Public Realm edited by Justin Hollander and Ann Sussman.

From the abstract:

This chapter introduces OpenStreetMap—a crowdsourced, worldwide mapping project and geospatial data repository—to illustrate its usefulness in quickly and easily analyzing and visualizing planning and design outcomes in the built environment. It demonstrates the OSMnx toolkit for automatically downloading, modeling and visualizing spatial data from OpenStreetMap. We explore patterns and configurations in street networks and buildings around the world computationally through visualization methods—including figure-ground diagrams and polar histograms—that help compress urban complexity into comprehensible artifacts that reflect the human experience of the built environment. Ubiquitous urban data and computation can open up new urban form analyses from both quantitative and qualitative perspectives.

For more, check out the chapter.

Categories
Planning

Off the Grid… and Back Again?

My article “Off the Grid… and Back Again? The Recent Evolution of American Street Network Planning and Design” has been published by the Journal of the American Planning Association and won the 2020 Stough-Johansson Springer Award for best paper. It identifies recent nationwide trends in American street network design, measuring how urban planners abandoned the grid and embraced sprawl over the 20th century, but since 2000 these trends have rebounded, shifting back toward historical design patterns. In this post I discuss these findings and visualizations across the US today as well as over time, then discuss my analysis methods.

Map of where street grids exist today across the US, made with OSMnx and Python