Friday, December 23, 2016

A history of global living conditions: a big picture of human development in 6 charts

It is hard not to be a pessimist these days. As 2016 comes to an end, it leaves us with that bitter feeling of "WTF world!". In gloomy days like these, having a long term perspective on human development can help us alleviate this feeling.

The image below brings 6 charts that give a historical perspective on human development (detailed and interactive charts here). They show the big picture of some of the remarkable improvements we have seen in the world in the last 200 years, with less poverty and tyranny and with more education and better health conditions.

This image comes from Our World in Data (OWID), a fantastic online publication that shows how living conditions are changing in the world with the best available on wide range of topics including health, food, energy, institutions, culture, education, technology, war and peace, etc. I am proud that OWID is produced at the University of Oxford. It was created by  Max RoserEsteban Ortiz Ospina and Jaiden Mispy

The OWID website is a great source of information, particularly if you're feeling too pessimistic about the world  or if you feel like procrastinating a bit, like me 

"One reason why we do not see progress is that we are unaware of how bad the past was." (Roser et al, OWID)

Wednesday, December 21, 2016

Cyber-attacks and the vulnerability of smart cities

A few weeks ago, anonymous hackers attacked the computers that run the public transport system of San Francisco, which wouldn't take any payments from passengers. The hackers demanded a ransom of 100 Bitcoin (about $73,000) but didn't get any money. Full story here, by Jack Stewart.

If I'm not mistaken, this is the first case a cyber-attack targets a public transport system. Certainly, this will not be the last one. This kind of event is likely to become more common as cities adopt 'smart' strategies of urban management that increasingly connect public services to integrated systems and the 'internet of things'.

Perhaps a good topic for a PhD project, if anyone is interested.

R Links

  1. A new R package establishes an interface between R and QGIS - RQGIS , and a video tutorial showing the new ArcGIS interface for R

  2. PISA 2015 – how to read/process/plot PISA data with R

  3. bayesPop, the package for Bayesian population projections used by the UN, by Adrian Raftery via Bernardo L Queiroz. Here is the paper

  4. Improving R animated GIFs with tweenr,by Leonard Kiefer

  5. Simple and interactive R Graph Catalog

  6. An interactive color chooser for #rstats

  7. Creating tilted and stacked maps in R using ggplot2

  8. Urška Demšar et al have written an script in R to visualize Stacked Space-Time Densities around trajectories. The related paper is here

credit: Urška Demšar

Tuesday, December 20, 2016

Mapped history of population expansion in Brazil

Early this month we shared an animation created by Nathan Yau mapping the history of population expansion in the US.

Here is a relatively simpler but still a nice animation of population growth in Brazilian municipalities between 1872 and 2010. This gif is based on population census data and it was created by a data visualization team at Nexo, which is one of the best news websites in Brazil.

credit: Nexo

Here is a similar animation but distorting land mass according to population size, like in those maps that got popularised by Ben Benjamin.

credit: Nexo

Saturday, December 17, 2016

Urban Picture

Truly sad pictures of the Syria's civil war back in 2014, and recent pictures here and here. Since then, the situation has gotten depressingly worse in the country.

Damascus, Syria, January-2014

This picture taken the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) shows residents of the besieged Palestinian camp of Yarmouk, queuing to receive food supplies, in Damascus, Syria, on January 31, 2014.

If you would like to help, consider donating to organizations with the greatest capacity to make a difference amid this devastation.

Wednesday, December 14, 2016

Open Research position at the Transport Studies Unit, Oxford University

Please spread the word:

The Transport Studies Unit (TSU) and the School of Geography and the Environment at Oxford University are advertising a 5-year post of Research Lecturer in Transport Studies. Applications deadline: 30 January 2017. Full details can be found here.

As some of you will know, I am in my 4th year of my PhD at TSU, under the supervision of Tim Schwanen and David Banister. I have to say this has been a fantastic and humbling experience and I feel extremely privileged to be part of this institution, which I would highly recommend to prospective students and researchers. TSU is a relatively small research group with some extremely smart researchers in an incredibly vibrant department at one of the top universities in the world. 

ps. the city of Oxford is also lovely but the the weather is not exactly what you would find in Hawaii.

Sunday, December 11, 2016

Comparing house price trends worldwide

Leonard Kiefer has a new post where he presents some interesting analysis of global house price trends. Lonards has used data from the international house price database, organized by the Dallas Federal Reserve Bank.

The analysis is written in R and the code is available at the bottom of his post. Thanks Leonard!

ps. don't forget to check the related links at the bottom of this post.

credit: Leonard Kiefer

Related Links:

Saturday, December 10, 2016

Navigation Before Google Maps

Wednesday, December 7, 2016

summary: Distributive justice and equity in transportation

Hi all, the 1st paper of my thesis is now published \o/. You can download it here. If you cannot access the PDF, just let me know and I'll send it to you. Here is a summary of the paper:

Pereira, R. H. M., Schwanen, T., Banister, D. (2017). Distributive justice and equity in transportation. Transport Reviews, 37(2), doi:10.1080/01441647.2016.1257660

What's it about?

As I've mentioned before in the blog, this is a review paper on distributive justice in transportation, particularly focused on transport accessibility and social exclusion. While transport planning has been traditionally concerned with improving the efficiency of transport systems, this paper argues why policy makers and researchers should take issues of equity more seriously and it discusses how justice could be considered in evaluating the distributional aspects of who benefits from transport policies and investments.

In short, the paper:
  • reviews how issues of equity and social exclusion have been covered in the transport and mobilities literatures 
  • reviews five key theories of justice (utilitarianism, libertarianism, intuitionism, Rawls’ egalitarianism, and Capability Approaches) and critically evaluates the insights they generate when applied to transport 
  • proposes a distributive justice framework for policy evaluation, with a focus on transport accessibility and social exclusion

Core ideas of the paper

In the final part of the paper, we build a dialogue between Rawls’ egalitarianism and the Capabilities Approach to propose that distributive justice concerns over transport disadvantage and social exclusion should focus primarily on accessibility as a human capability. This means that, in policy evaluation, a detailed analysis of the distributional effects of transport policies should take account of the setting of minimum standards of accessibility to key destinations and the extent to which these policies respect individuals’ rights and prioritise disadvantaged groups, reduce inequalities of opportunities, and mitigate transport externalities. A full account of justice in transportation requires a more complete understanding of accessibility than traditional approaches have been able to deliver to date.

As you will have noticed, there are five key points developed in the paper. I should try to unpacked them in another post in the future.
  1. Focus on accessibility as a human capability
  2. Minimum standards of accessibility to key destinations 
  3. Respect for individuals’ rights 
  4. Prioritization of disadvantaged groups and reduction of inequalities of opportunities
  5. Mitigation of transport externalities

Practical implications

For now, I close this post with some of the practical implications of the ideas proposed in the paper:

  • "Some of the practical implications of this perspective can be illustrated with issues that commonly arise in cities with investments in public transport (e.g. metro and bus rapid transit developments) and cycling/walking. These types of investments can be good ways to prioritise transport modes which are more widely used by low-income classes. To be considered fair, however, these investments should not override the social rights of families threatened with eviction due to the infrastructure projects. The distributional effects of such investments should be evaluated in terms of the extent to which they reduce inequalities in transport accessibility, particularly by improving the accessibility levels of low-income public transport-dependent groups to key destinations such as employment opportunities, healthcare, and education services. According to this approach, the design of those transport projects (including the design of vehicles, stations, cycle paths, etc.) must be inclusive towards social groups such as the elderly and disabled in order to minimise the impact that non-chosen disadvantages have on people’s capacity to access activities. Moreover, this perspective also calls for complementary policies that discourage car use (e.g. congestion/parking charge and fuel tax) in highly congested and polluted areas to mitigate the negative externalities imposed by drivers on everyone else, particularly on vulnerable populations" p.15-16
I will be glad if some of you have read this far without falling asleep. 

Tuesday, December 6, 2016

Mapped history of population expansion in the US

Great data visualization created by Nathan Yau using R and NHGIS data. Nathan's website Flowing Data is one of my all time favorite websites and I strongly recommend you check it out.

Friday, December 2, 2016

Brasilia, 32 years of urban expansion

Google Earth Engine has released new data for their project Timelapse, which combines over 5 million satellite images acquired over the past three decades and allows for a zoomable video of land transformations at a global scale. You can play around  procrastinate  on their website zooming in different areas. I find Dubai and Las Vegas particularly interesting. There is a good playlist on Youtube!

This is the timelapse of Brasilia (Federal District), my hometown. During this period between 1984 and 2016, the population of Brasilia went from approx. 1.2 million to 2.9 million. The video shows some very interesting transformations including the expansion of poor settlements largely undeserved by urban infra-structure in the south and southwest of the city, but also some illegal occupations of protected areas by middle- and high-income gated communities in the east and north-east parts of the city.

Tuesday, November 29, 2016

The Social Dilemma of Driverless Cars

Iyad Rahwan presents in a TEDx his recently published paper on the the social dilemma of driverless cars (arXiv version here). HT Cesar Hidalgo.

You should try out the Moral Machine

Related link

Monday, November 28, 2016

Japan fact of the day

You know that 30-metre sinkhole on a road in Japan? It was fixed in just a couple of days.

UPDATE: November 28th, Japan's giant sinkhole is sinking again just a month after it had been repaired.

image credit: AP , The Guardian

Sunday, November 27, 2016

Cycling infrastructure and gender

A few days ago, I share a paper by Roger Beecham (Twitter) exploring gendered cycling behaviors in London. The paper brings a very interesting descriptive analysis of over 10 million journeys made by members of London's Cycle Hire Scheme.

A recent study by Rachel Aldred (Twitter) and colleagues sheds some more light on this debate with a review paper on how infrastructure preferences vary by gender and by age.

In this paper, we represent a systematic review of stated preference studies examining the extent to which cycle infrastructure preferences vary by gender and by age. A search of online, English-language academic and policy literature was followed by a three-stage screening process to identify relevant studies. We found 54 studies that investigated whether preferences for cycle infrastructure varied by gender and/or by age. Forty-four of these studies considered the extent of separation from motor traffic. The remainder of the studies covered diverse topics, including preferred winter maintenance methods and attitudes to cycle track lighting. We found that women reported stronger preferences than men for greater separation from motor traffic. There was weaker evidence of stronger preferences among older people. Differences in preferences were quantitative rather than qualitative; that is, preferences for separated infrastructure were stronger in some groups than in others, but no group preferred integration with motor traffic. Thus, in low-cycling countries seeking to increase cycling, this evidence suggests focusing on the stronger preferences of under-represented groups as a necessary element of universal design for cycling.

Urban Picture

Iberian Peninsula (Spain and Portugal), 2014

Friday, November 25, 2016

Carmageddon and Jamzilla in Los Angeles

I have already posted in the blog about the The Black Hole Theory of Highway Investment. For this matter, LA's 405 freeway is quite an iconic case as it has been the stage of 'Carmageddons' and 'Jamzillas' over the years.

Happy thanksgiving to our friends in LA.

Related links:

Wednesday, November 23, 2016

The Age of Data

BBC Four has a produced a fascinating documentary on The Joy of Data, presented by the great Hannah Fry (Twitter).

Friday, November 18, 2016

Quote of the day: measurement

'Not everything that can be measured is important, and not everything that is important can be measured'

I heard this sentence the other day, but apparently the original one is a bit different.

Thursday, November 17, 2016

Exploring gendered cycling behaviors in London

Beecham, R., &; Wood, J. (2014). Exploring gendered cycling behaviours within a large-scale behavioural data-set. Transportation Planning and Technology, 37(1), 83-97.

Analysing over 10 million journeys made by members of London's Cycle Hire Scheme, we find that female customers' usage characteristics are demonstrably different from those of male customers. Usage at weekends and within London's parks characterises women's journeys, whereas for men, a commuting function is more clearly identified. Some of these variations are explained by geo-demographic differences and by an atypical period of usage during the first three months after the scheme's launch. Controlling for each of these variables brings some convergence between men and women. However, many differences are preserved. Studying the spatio-temporal context under which journeys are made, we find that women's journeys are highly spatially structured. Even when making utilitarian cycle trips, routes that involve large, multi-lane roads are comparatively rare, and instead female cyclists preferentially select areas of the city associated with slower traffic streets and with cycle routes slightly offset from major roads.

credit: Beecham & Wood (2014)

ps. Interesting paper. I'm not sure what exactly the authors mean by "utilitarian cycle trips", though. I would like to see a more in depth discussion on the root causes of travel behavior differences by gender. It's a great work, though and the authors have a another paper where they focus on the methodology they've used.

Wednesday, November 9, 2016

Urban Picture


I've never felt so ashamed of being American... and I'm not even American.

There will be a flood of articles on this issue. I have really liked these two so far.

Monday, November 7, 2016

Racial discrimination and the sharing economy

Last year, a study by Edelman and Luca found robust evidence of racial discrimination among New York City landlords on Airbnb. More recently, a new study also brought evidence of racial discrimination among drivers of ride-sharing services including Uber, Lyft, and Flywheel (see abstract of the paper below).

The new era of big data opens lots of opportunities for research on social and racial discrimination on the web, including an emerging issue of algorithmic discrimination. On a related topic, Zeynep Tufekci has a great Ted talk about machine intelligence and morality.

Ge, Y., et al. (2016). Racial and Gender Discrimination in Transportation Network Companies (No. w22776). National Bureau of Economic Research.
Passengers have faced a history of discrimination in transportation systems. Peer transportation companies such as Uber and Lyft present the opportunity to rectify long-standing discrimination or worsen it. We sent passengers in Seattle, WA and Boston, MA to hail nearly 1,500 rides on controlled routes and recorded key performance metrics. Results indicated a pattern of discrimination, which we observed in Seattle through longer waiting times for African American passengers—as much as a 35 percent increase. In Boston, we observed discrimination by Uber drivers via more frequent cancellations against passengers when they used African American-sounding names. Across all trips, the cancellation rate for African American sounding names was more than twice as frequent compared to white sounding names. Male passengers requesting a ride in low-density areas were more than three times as likely to have their trip canceled when they used a African American-sounding name than when they used a white-sounding name. We also find evidence that drivers took female passengers for longer, more expensive, rides in Boston. We observe that removing names from trip booking may alleviate the immediate problem but could introduce other pathways for unequal treatment of passengers.

Sunday, November 6, 2016

Income segregation at the block level

Herwig Scherabon, an incredibly talented graphic designer, has created this artistic representation of income segregation of Los Angeles, Chicago and New York at the block level. These pieces are shortlisted for the Information is Beautiful Awards. Thanks Linda Regber for the pointer.

Click on the images for higher resolution.

                           Chicago                                                        Los Angeles

New York

Friday, November 4, 2016

Wednesday, November 2, 2016

The Impact of Urban Appearance

We have mentioned the work of Cesar Hidalgo (twitter) in this blog a few times already but he keeps coming up with new interesting research . As many will know, Hidalgo and his team have a project called Place Pulse, in which they use computer vision techniques to analyze snapshots of google street view and crowdsource people's perception on city’s physical appearance. Here are my three highlight of the project so far.

The research possibilities here are endless, so I'm sure I'll be posting updates on this project again in the future. Don't forget to input some of your own perceptions to the project.

Saturday, October 29, 2016

Distributive justice and equity in transportation

Good news! The 1st paper of my thesis has finally been accepted for publication \o/

 This is the first theoretical paper I've dared to write and I can promise this is a good read for those of us with insomnia issuesIt is a literature review on distributive justice and equity in transportation policies, particularly focused on transport accessibility and social exclusion. The paper provides the general theoretical framework of the dissertation.

The paper should be published early next year as part of a special issue on transportation equity in the journal Transport Reviews. In case you are interested  or have sleeping problems , you can find the final manuscript accepted by the editors here. If you want to access the published version, just drop me an email.

Pereira, R. H. M., Schwanen, T., & Banister, D. (2016). Distributive justice and equity in transportation. Transport Reviews, 0(0), 1–22. doi:10.1080/01441647.2016.1257660

Over the past decades, transport researchers and policymakers have devoted increasing attention to questions about justice and equity. Nonetheless, there is still little engagement with theories in political philosophy to frame what justice means in the context of transport policies. This paper reviews five key theories of justice (utilitarianism, libertarianism, intuitionism, Rawls’ egalitarianism, and Capability Approaches), and critically evaluates the insights they generate when applied to transport. Based on a dialogue between Rawlsian and Capability Approaches, we propose that distributive justice concerns over transport disadvantage and social exclusion should focus primarily on accessibility as a human capability. This means that, in policy evaluation, a detailed analysis of distributional effects of transport policies should consider minimum standards of accessibility to key destinations and the extent of which these policies respect individuals’ rights and prioritize disadvantaged groups, reduce inequalities of opportunities and mitigate transport externalities. A full account of justice in transportation requires a more complete understanding of accessibility than traditional approaches have been able to deliver to date.

* From paper submission (Feb 2015) to acceptance letter (Oct 2016), the whole process took 1 year and 8 months with a couple of iterations with three reviewers who were really generous with their time and detailed comments. 

Thursday, October 27, 2016

The impact of public transport on traffic congestion

"... we find that average highway delay increases 47 percent when transit service ceases."

This is from a 2014 paper by Michael Anderson (Berkeley), analyzing the impacts of public transport on traffic congestion in Los Angeles. An ungated working-paper version is available here.  Via Renato Vieira.

Anderson, Michael L.. 2014. "Subways, Strikes, and Slowdowns: The Impacts of Public Transit on Traffic Congestion." American Economic Review, 104(9): 2763-96.

Public transit accounts for 1 percent of U.S. passenger miles traveled but attracts strong public support. Using a simple choice model, we predict that transit riders are likely to be individuals who commute along routes with severe roadway delays. These individuals' choices thus have high marginal impacts on congestion. We test this prediction with data from a strike in 2003 by Los Angeles transit workers. Estimating a regression discontinuity design, we find that average highway delay increases 47 percent when transit service ceases. We find that the net benefits of transit systems appear to be much larger than previously believed.

Despite this really interesting finding, I just would like to note that the main purpose of public transport is not to reduce congestion, as many politicians and the general media like to think. The purpose of public transport  is to help people to access activities and opportunities. Although this might sound a subtle difference for some people, this difference has serious implications for how one should plan and evaluate transport policies.

Sunday, October 23, 2016

Urban Picture

Chicago towers over lake Michigan
by Nick Ulivieri (2016)

Thursday, October 20, 2016

PhD feelings

This is how doing a PhD feels like. I'm the clumsy flying fish

Tuesday, October 18, 2016

Quote of the Day: Bureaucracy

Saturday, October 15, 2016

Visualizing the space-time geography of flow data

Till Nagel and Christopher Pietsch have created an art installation that allows one to visualize and compare the spaces of flow created by bike-sharing systems in New York City, Berlin, and London. The name of the project is city flow, a comparative visualization environment of urban bike mobility. They have recently published a paper (co-authored with Marian Dörk) with more technical information about their project.

These guys are doing a fabulous work with design, and I believe they're really pushing the boundary of data visualization in urban and transport studies with new tools to visualize the space-time geography of flow data. 

Take a look at how easy it gets to explore trajectories of cyclists in space and time with their tool.

Tuesday, October 11, 2016

Cycle infrastructure is democracy in motion

A picture is worth a thousand words:

Sunday, October 9, 2016

The Social Fabric of Cities

Vinicus Netto (Twitter) has published a new book called 'The Social Fabric of Cities' (contents and introduction available here. There is also a website of the book). This one is going straight to my reading pile and I'm sure it will be of interest for all the 100 million readers of this blog. Here are the foreword by Mike Batty and a description of the book.


"Linking the physical to the social city is the challenge of our times. This is one of the first attempts to systematically do so, and Netto brilliantly succeeds in showing how encounters, segregation, movement and interaction are reflected in our understanding of the form and function of the city." (Michael Batty, CASA, UCL)

Book description:

Bringing together ideas from the fields of sociology, economics, human geography, ethics, political and communications theory, this book deals with some key subjects in urban design: the multidimensional effects of the spatial form of cities, ways of appropriating urban space, and the different material factors involved in the emergence of social life. It puts forward an innovative conceptual framework to reconsider some fundamental features of city-making as a social process: the place of cities in encounters and communications, in the randomness of events and in the repetition of activities that characterise societies. In doing so, it provides fresh analytical tools and theoretical insights to help advance our understanding of the networks of causalities, contingencies and contexts involved in practices of city-making. 
In a systematic attempt to bring urban analysis and research from the social sciences together, the book is organised around three vital yet relatively neglected dimensions in the social and material shaping of cities: (i) Cities as systems of encounter: an approach to urban segregation as segregated networks; (ii) Cities as systems of communication: a view of shared spaces as a means to association and social experience; (iii) Cities as systems of material interaction: explorations on urban form as an effect of interactivity, and interactivity as an effect of form.