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urban planning

Mapping and measuring urban places: Are we there yet? (Part 2/2)

David Mason's picture
Photo by Anton Balazh via Shutterstock

My previous blog post surveyed some of the recent trends in developing global measures of urbanization. In this post, I want to turn to a brief discussion for scholars and practitioners on some possible applications and areas of focus for ongoing work:
 
[Download draft paper "Bright Lights, Big Cities: a Review of Research and Findings on Global Urban Expansion"]
 
While there are a number of different maps for documenting urban expansion, each has different strengths and weaknesses in application. Coarser resolution maps such as MODIS can be used for mapping the basic contours of artificial built-up areas in regional and comparative scales. On the other hand, high-resolution maps are best suited for individual cities, as algorithms can be used to identify and classify observed colors, textures, shading, and patterns into different types of land uses. These levels of detail are difficult to use for reliable comparisons between cities as the types of building materials, structure shapes, light reflectivity, and other factors can vary widely between countries and regions.
 
Nonetheless, there are a number of applications for policymakers in this regard, from identifying and mapping green spaces and natural hazard risks to identifying and tracking areas of new growth, such as informal settlements. However, such approaches to land use detection require careful calibration of these automated methods, such as cross referencing with other available maps, or by “ground truthing” with a sample of  street-level photos of various types of buildings and land cover as reference inputs for automation. One solution to this is the use of social media and geo-coded data to confirm and monitor changes in urban environments alongside the use of high-resolution satellite imagery.
 
Nighttime light maps also have gained traction as measures of urban extent and as ways to gauge changes in economic activity in large urban centers. They are probably less useful for documenting smaller settlements, which may be dimmer or have little significant variation in brightness. It is important to correct these types of maps for “overglow” measurement effects—where certain light may “bleed” or obscure the shapes and forms of very large, bright urban areas in relation to adjacent smaller and dimmer settlements (newer VIIRs maps have made some important advances in correcting this).

When cities forget about pedestrians, big data and technology can serve as a friendly reminder

Bianca Bianchi Alves's picture
Photo: Lazyllama/Shutterstock
Paraisópolis, a nationally famous slum area in São Paulo, Brazil, is one of those bustling communities where everything happens. Despite being located in the middle of the city, it managed, unlike other poor slum areas, not to be reallocated to make room for more expensive housing or public infrastructure. The area boasts vibrant community life, with more than 40 active NGOs covering issues that range from waste management and health to ballet and cooking. Recently, the area also benefited from several community upgrading programs. In particular, investments in local roads have facilitated truck access to the community, bringing in large and small retailers, and generating lively economic activity along with job opportunities for local residents.

As we continue our efforts to increase awareness around on-foot mobility (see previous blog), today, I would like to highlight a project we developed for Paraisópolis.

While most of the community has access to basic services and there are opportunities for professional enhancement and cultural activities, mobility and access to jobs remains a challenge. The current inequitable distribution of public space in the community prioritizes private cars versus transit and non-motorized transport. This contributes to severe congestion and reduced transit travel speed; buses had to be reallocated to neighboring streets because they were always stuck in traffic. Pedestrians are always at danger of being hit by a vehicle or falling on the barely-existent sidewalks, and emergency vehicles have no chance of getting into the community if needed. For example, in the last year there were three fire events—a common hazard in such communities—affecting hundreds of homes, yet the emergency trucks could not come in to respond on time because of cars blocking the passage.

Two ways to make Africa’s cities more livable, connected and affordable

Ede Ijjasz-Vasquez's picture

Urban population in Africa will double within the next 25 years and reach 1 billion people by 2040, but concentration of people in cities has not been accompanied by economic density.

Typical African cities share three features that constrain urban development and create daily challenges for businesses and residents: they are crowded, disconnected, and therefore costly, according to a new report titled “Africa’s Cities: Opening Doors to the World.”

Traffic jams, pollution, road crashes: Can technology end the woes of urban transport?

Shomik Mehndiratta's picture
Photo: Noeltock/Flickr
Will technology be the savior of urban mobility?
 
Urbanization and rising incomes have been driving rapid motorization across Asia, Africa, and Latin America. While cities are currently home to 50% of the global population, that proportion is expected to increase to 70% by 2050. At the same time, business-as-usual trends suggest we could see an additional 1 billon cars by 2050, most of which will have to squeeze into the already crowded streets of Indian, Chinese, and African cities.
 
If no action is taken, these cars threaten literally to choke tomorrow’s cities, bringing with them a host of negative consequences that would seriously undermine the overall benefits of urbanization: lowered productivity from constant congestion; local pollution and rising carbon emissions; road traffic deaths and injuries; rising inequity and social division.
 
However, after a century of relatively small incremental progress, disruptive changes in the world of automotive technology could have fundamental implications for sustainability.
 
What are these megatrends, and how can they reshape the future of urban mobility?

Eight stubborn facts about housing policies

Luis Triveno's picture
A low-income residential neighborhood in Mumbai, India. Photo: Simone D. McCourtie / World Bank
As John Adams famously warned, “facts are stubborn things” that we cannot wish away. Governments in the developing world are finally facing up to the increasing need for affordable housing: today 1.2 billion people live in substandard housing; by 2030, 3 billion will need new housing. While challenges may vary by country, I believe there are at least eight “stubborn facts” about housing policy that should not be ignored.

Building sustainable cities starts with smart urban design

Ede Ijjasz-Vasquez's picture
The global conversation about urban sustainability focuses primarily on the big picture: how to reduce the carbon footprint and energy consumption of cities? How can we provide the infrastructure and services necessary to meet the needs of a soaring urban population? How can cities create enough jobs for everyone?
 
These issues are critically important, no doubt. But what about the city itself as a physical space? What should a sustainable city "look like"? Are there any big design principles that all successful urban planners should follow?
 
Because urbanization is often a chaotic process, many countries feel like they don't have the time or resources to address those questions. Yet evidence has shown that considerations about urban form and design are anything but cosmetic: creating vibrant public spaces within a city, for instance, can boost competitiveness, improve health outcomes, and strengthen social cohesion.
 
In this video, Ede Ijjasz-Vasquez and Jon Kher Kaw delve deeper into the linkages between urban spaces and sustainability, and describe the many benefits that come with a well-designed city.
 
If you want to learn more about this topic, we invite you to discover our latest Sustainable Communities podcast.
 
Related:

Success when we deemed it failure? Revisiting sites and services 20 years later

Sumila Gulyani's picture
Between 1977 and 1997, the World Bank supported “sites and services” projects in 27 cities across India
A freshly-minted architect stood staring at a sea of toilets. Row after row of them, on small “housing plots” meant for low-income families who would build their house incrementally as their incomes and savings grew. The neighborhood was “planned” and provided with services—under a World Bank-supported “sites and services” project—to serve as the anti-thesis of and an antidote to the slums that were, at the time, increasingly becoming the only housing option for low-income families.

It was 1980 and the architect, Barjor Mehta, was deeply disappointed. There were no houses, no people and no chance that they would ever come, given the seemingly god-forsaken location—in an area called Arrumbakkam—so far from the city center in Madras (now Chennai). Having just completed his thesis on housing, he wrote a scathing news article in the Times of India denouncing the sites and services approach. Barjor wasn’t alone in his critique, and by the mid-1990s the World Bank had almost entirely abandoned such projects.

In October 2015, Barjor, now Lead Urban Specialist at the Bank, invited me to revisit Arumbakkam and other neighborhoods developed, between 1977 and 1997, under four Bank-supported sites and services projects: With my colleagues Kate Owens and Andrea Rizvi, I visited 15 of the 28 sites developed in Chennai and Mumbai. We also reviewed archival material, analyzed satellite images, and recently presented our preliminary findings. Now, Barjor and I agree that previous assessments of failure may have been both premature and erroneous. Why?

Can transit-oriented development change travel behavior in cities?

Wanli Fang's picture
Photo: Marius Godoi/Shutterstock
It is pretty easy to understand how and why land use patterns around public transit stations can influence the way we move around the city.

As more and more people live and work in a neighborhood with a limited land area, it becomes increasingly challenging to drive around without encountering congestion or to find a parking space easily. In this situation, public transit and non-motorized transport (NMT) become attractive alternatives for people who otherwise are reluctant to give up the comfort and flexibility of driving.

Conversely, as street blocks get bigger, people may find it takes too long to access public transit stations, which discourages the use of public transport facilities.

As straightforward as the logic may sound, the nature and magnitude of such influence are yet to be evaluated with solid empirical evidence. To take a closer look at the linkages between land use and travel behavior, I decided to study the case of Boston in the United States. I chose Boston because it boasts an effective public transit system, and was one of the first American cities to embrace transit-oriented development (TOD), an urban planning approach that promotes compact and mixed use development around public transit facilities.

Of tigers and elephants: The rise of cities in Asia

Judy Baker's picture
Rush hour traffic in Mumbai, India. Photo: Adam Cohn/Flickr
Over the next decade and a half the world will add a staggering 1.1 billion people to its towns and cities. About one half of this urbanization will happen in the regions of East and South Asia.
 
If history is any guide, this growth in urban population will provide tremendous opportunities for increasing prosperity and livability. One can look at the successes of a few Asian cities such as Tokyo, Seoul, and Singapore to demonstrate how, with the assistance of good policies, urbanization and economic development go hand-in-hand. More generally, no major country has ever reached middle-income status without also experiencing substantial urbanization.
 
Yet cities can grow in different ways that will affect their competitiveness, livability, and sustainability. The more successful cities of Asia have been effective at creating opportunities, increasing productivity, fostering innovation, providing efficient and affordable services for residents, and enhancing public spaces to create vibrant and attractive places to live. But many, many, more cities have neglected fundamental investments in critical infrastructure and basic services, and have mismanaged land, environmental and social policies. This has resulted in traffic congestion, sprawl, slums, pollution, and crime.
 
Among the many complexities of urban development that have contributed to success, two critical factors stand out – investing in strategic urban planning, and in good urban governance.

How public spaces will help change cities for the better

Gunes Basat's picture
Also available in: Español
Photo: Wajahat Syed/Flickr
Photo: Wajahat Syed/Flickr
How to make cities more livable for people? How to create good, inclusive and accessible public spaces for all?

I’m not an urban planner nor an architect. I’m not a sociologist or an anthropologist either. But based on my personal experience, I can tell why public spaces are important in people’s lives. Just close your eyes for a second and think about your favorite public space. What do you like to do over there most? Why do you think you love it there?

I like them because they provide green breather spaces in the city and provide a place for recreation, enjoyment and a sense of belonging.

However, after hearing from many prominent urban development experts at a recent World Bank-led “Urbanscapes Symposium”, I quickly realized that public spaces are more than this. It was striking to me to see and learn that, for others, public spaces are places where livelihoods are conducted and are essential spaces for social interaction, especially for the poor.

In that respect, providing people with new public spaces, where they can feel invited, welcome and safe, can encourage them to spend more time outside and foster interaction among lower income communities.

It should come as no surprise, then, that planning standards recommend devoting 15-20 % of land in cities to public open space… Yet most cities are falling short of that goal: in the United States, for instance, 75% of the 100 largest cities do not meet that requirement.

So how can we work with cities to help them create a better urban environment and leverage the potential of public spaces?

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