Thursday, March 22, 2018

8th International Congress Mobility and Transportation, Bogotá

I will be in Bogotá (Colombia) speaking at the 8th International Congress Mobility and Transportation on the first week of April (conference program here). I was kindly invited by TRANSMILENIO S.A, the company that runs the renowned Transmilenio BRT system. The event will gather policy makers, private operators, start ups and academics to discuss some of the main issues and challenges in urban transportation in Latin America.

 To my supervisors, if the ever read this  I know this will be a little distraction from writing by thesis, but it will be a unique opportunity to share my research with experts in the region and to meet some great people. Also, I'm excited that I'll share the floor with Robert Cervero on a panel about the impacts of public transport on cities.

I will be presenting part of my doctoral research, looking at how major transport policies implemented in Rio de Janeiro have impacted people's access to schools and jobs and increased social and spatial inequalities in access to opportunities (preprint of this paper). I will also talk a bit about a new paper where I analyze the TransBrasil BRT project in Rio and estimate its likely future impacts on accessibility inequalities in the city (preprint here). I'll post more info about this paper soon.

Monday, March 19, 2018

"Even wealthy families, good neighborhoods and two parents can’t protect black boys from racism"

The title is this blog post comes from Emily Badger (Twitter), who has written a great piece for the NYT, covering the latest study of Raj Chetty and colleagues. Using a unique dataset, the study shows that black men consistently earn less than white men, regardless of whether they're raised poor or rich. The full paper is here.

The study is part of The Equality of opportunity Project, an ambitious and groundbreaking project led by Chetty. I've posted about the project in this blog a few years ago.

Thursday, March 15, 2018

Using R to Predict Route Preferences in Bike Sharing

Daniel Patterson has written a really great post/tutorial on how to use R to identify what routes are most frequently used by cyclists in the bike sharing program of the Twin Cities area of Minnesota. It's a good and quick read, you should check it out.

Daniel's analysis was conducted using stplanr, an R package for sustainable transport planning. This package was developed by Robin Lovelace, who is a great enthusiast for active transport and one of the most important developers for spatial and transport analysis in R.

credit: Daniel Patterson

Friday, March 9, 2018

Quote of the Day

And damn, I'm good at this!   the making mistakes part, at least 

I saw this quote on via Programming Wisdom, great account to follow on Twitter.

Wednesday, March 7, 2018

Political populism and the revenge of the places that don’t matter

Earlier this year, Andrés Rodríguez-Pose (Twitter) published an interesting article where he points out to a pattern in the relationship between the outcomes of some national elections/referendums and the regional development inequalities in some countries. This is the core of Andrés' argument:
Persistent poverty, economic decay and lack of opportunities cause discontent in declining regions, while policymakers reason that successful agglomeration economies drive economic dynamism, and that regeneration has failed. This column argues that this disconnect has led many of these ‘places that don’t matter’ to revolt in a wave of political populism with strong territorial, rather than social, foundations.

According to Andrés Rodríguez-Pose, this help us understand the rise of populism we have recently witnessed in the national elections/referendums in Thailand, Germany, UK, France, USA and now in Italy. The strength of this apparently simple idea becomes evident when one looks at the spatial distribution of electoral outcomes vis-a-vis the social and economic disparities within those countries.

We have elections in Brazil this year. I’m looking forward to seeing whether the results are going to follow the pattern noted by Andrés. I’m afraid yes, but in a slightly different way. Like in many other countries, Brazil is also seeing the rise of a right-wing conservative populist wave. I believe this wave will be strong in the poorest regions and economically declining cities of the country, following the pattern of the "revenge of the places that don’t matter". However, my hunch is that this wave is going to be particularly strong in the rural areas that are thriving economically, not because of economic reasons but because these areas are traditionally conservative Moreover, I think it is really hard to say what is going to happen in the poor rural areas of the poorest stagnant regions of the country (North and Northeast). In the recent past, these regions have leaned towards the often populist center-left Labor Party, but the political importance of this party has been tremendously shaken in recent years due to corruption scandals and a a contentious impeachment process. If these regions keep their historical support to the Labor Party, this would contradict Andrés' conjecture.

These are only two small particularities that I think will make the Brazilian case diverge a bit from the pattern noted in the conjecture of the "revenge of the places that don’t matter". I might be wrong and I hope I am. In any case, the Brazilian election will be a good opportunity to put this conjecture to test.

image credit: Andrés Rodríguez-Pose

Tuesday, March 6, 2018

Scientific Communication

Quick note to say I've been a bit absent from blogging while I'm writing up  stressing out about  my PhD thesis.  I keep tweeting a bit more often though.

Cartoon by Tom Gauld, HT Arthur Charpentier

Sunday, February 18, 2018

Saturday, February 17, 2018

Urban Picture

Hisashimichi interchange in the city of Hachioji, in Tokyo Metropolitan Area.  You can see this interchange on OpenStreetMap, here. Thanks Pedro Geaquinto for sharing the OSM link!

photo credit: ?

Friday, February 9, 2018

A survey of the literature on mobile phone datasets analysis

A good paper giving a nice overview of the research using mobile phone datasets (mostly CDR data). A lot of interesting research looking at human mobility patterns, spatial and temporal networks, urban and regional development. This paper is already 3 years old, though, and things move fairly quickly in this type of research.

Some of the authors covered in this review are on Twitter. I've tagged them here and here in case you'd like to follow them.

Blondel, V. D., Decuyper, A., & Krings, G. (2015). A survey of results on mobile phone datasets analysis. EPJ Data Science, 4(1), 10.

In this paper, we review some advances made recently in the study of mobile phone datasets. This area of research has emerged a decade ago, with the increasing availability of large-scale anonymized datasets, and has grown into a stand-alone topic. We survey the contributions made so far on the social networks that can be constructed with such data, the study of personal mobility, geographical partitioning, urban planning, and help towards development as well as security and privacy issues.

image credit: Wang et al. 2009

Thursday, February 8, 2018

Waiting for my supervisors' feedback



More work needs to be done ... of course

Carnival is taken very seriously in Brazil

And now, back to writing.

Wednesday, February 7, 2018

Thoughtful thread on the future of shared, autonomous and electric mobility

For those not familiar with Twitter, click on this link to read the full thread.

On a related note, Tim Schwanen pointed out to this interesting piece about the State led emerging role of China in electric mobility industry.

Assorted Links

  1. Sprawling Mayan 'cities' uncovered under Guatemala jungle using LIDAR data - "The study estimates that roughly 10 million people may have lived within the Maya Lowlands"

  2. The World's 15 Most Complex Subway Maps and our cognitive limits: "Multimodal transportation systems in large cities have thus already exceeded human cognitive limits and, consequently, the traditional view of navigation in cities has to be revised substantially"

Thursday, February 1, 2018

How much residential space could you rent with $1,500 in 30 global cities?

I saw this chart on Twitter via Simon Kuestenmacher.

Infographic: Where Renters Get the Most and Least Space | Statista You will find more statistics at Statista

Related posts:
  1. Comparing house price trends worldwide
  2. The effects of rent control on tenants, landlords, and inequality
  3. Aggregate homeownership rates for different countries
  4. Map of real estate prices in Sao Paulo
  5. Empty spaces in the crowd: Residential vacancy in São Paulo

UPDATE [6 Feb 2018] Apparently, the data is for 2016. The source of the date is a real state intelligence company called Yardi Matrix. They have another version of the chart that includes the 100 most populous cities in the US.

How much residential space could you rent with $1,500 in the 100 most populous US cities?

Tuesday, January 30, 2018

Oxford from above

A beautiful panoramic view of Oxford from above (via BBC Oxford). Apparently you need to go on Facebook to get the interactive version of the picture below.

In case you would like to see how Oxford looks like on the ground, there is actually a camera that streams in real time the day-to-day of Broad Street, one of the main roads in the city. Or, you can explore Oxford on Google Street View and go inside some colleges and libraries

ps warning: Oxford is always NOT always sunny as you see on Google Street View. It rarely is, really.

Sunday, January 28, 2018

The health and economic benefits of cycling network expansion in 167 European cities

A recent study has analyzed the associations between cycling network length and mode share, and estimated the health impacts of the expansion of cycling networks across 167 cities in 11 European countries. According to the study, if all 167 cities assessed achieved a 24.7% bicycle mode share, over 10,000 premature deaths could be avoided annually. The study was led by Natalie Mueller and conducted by a network of European researchers. Thanks Christian Brand for the pointer.

Mueller, N., et al. (2018). Health impact assessment of cycling network expansions in European cities. Preventive medicine. (in press).

We conducted a health impact assessment (HIA) of cycling network expansions in seven European cities. We modeled the association between cycling network length and cycling mode share and estimated health impacts of the expansion of cycling networks. First, we performed a non-linear least square regression to assess the relationship between cycling network length and cycling mode share for 167 European cities. Second, we conducted a quantitative HIA for the seven cities of different scenarios (S) assessing how an expansion of the cycling network [i.e. 10% (S1); 50% (S2); 100% (S3), and all-streets (S4)] would lead to an increase in cycling mode share and estimated mortality impacts thereof. We quantified mortality impacts for changes in physical activity, air pollution and traffic incidents. Third, we conducted a cost–benefit analysis. The cycling network length was associated with a cycling mode share of up to 24.7% in European cities. The all-streets scenario (S4) produced greatest benefits through increases in cycling for London with 1210 premature deaths (95% CI: 447–1972) avoidable annually, followed by Rome (433; 95% CI: 170–695), Barcelona (248; 95% CI: 86–410), Vienna (146; 95% CI: 40–252), Zurich (58; 95% CI: 16–100) and Antwerp (7; 95% CI: 3–11). The largest cost–benefit ratios were found for the 10% increase in cycling networks (S1). If all 167 European cities achieved a cycling mode share of 24.7% over 10,000 premature deaths could be avoided annually. In European cities, expansions of cycling networks were associated with increases in cycling and estimated to provide health and economic benefits.

credit: Mueller et al. (2018)

Friday, January 26, 2018

Amserdam in the 70s

A nice photograph that makes us think how of many cities and their transport systems in the world today look very much similar to how Amsterdam used to be in the 1970s. A bit more on this topic on this previous post:  "We are not Amsterdam".

picture via Old Pics Archive

Thursday, January 25, 2018

A review of 85 Agent-Based Modelling platforms and tools

A recent paper has conducted a comprehensive literature survey comparing 85 Agent-Based Modelling platforms and tools according to the easy of development (simple-moderate-hard) as well as their capabilities (light-weight to extreme-scale). Via Danilo Freire (Twitter)

Abar, S. et al (2017). Agent Based Modelling and Simulation tools: A review of the state-of-art software. Computer Science Review. Volume 24, May 2017, Pages 13-33

The key intent of this work is to present a comprehensive comparative literature survey of the state-of-art in software agent-based computing technology and its incorporation within the modelling and simulation domain. The original contribution of this survey is two-fold: (1) Present a concise characterization of almost the entire spectrum of agent-based modelling and simulation tools, thereby highlighting the salient features, merits, and shortcomings of such multi-faceted application software; this article covers eighty five agent-based toolkits that may assist the system designers and developers with common tasks, such as constructing agent-based models and portraying the real-time simulation outputs in tabular/graphical formats and visual recordings. (2) Provide a usable reference that aids engineers, researchers, learners and academicians in readily selecting an appropriate agent-based modelling and simulation toolkit for designing and developing their system models and prototypes, cognizant of both their expertise and those requirements of their application domain. In a nutshell, a significant synthesis of Agent Based Modelling and Simulation (ABMS) resources has been performed in this review that stimulates further investigation into this topic.

By the way, one of the large-scale models that is relatively easy to use is the UrbanSim model, developed by Paul Waddell's team at Berkeley and which is freely available on GitHub. MATSim scales well with really large simulations and it's also open-source available on GitHub.

click on the image to enlarge it or go read the paper :) 

Tuesday, January 23, 2018

My talk at Transforming Transportation 2018 and personal impressions on TRB

The two conferences have quite different audiences, though, and I had to adapt my presentation accordingly. While TRB is a typical academic conference, TT is more policy oriented and mostly attended by high-level practitioners. So it was a bit of a challenge to tailor the presentation for TT, particularly because I was only given about 8 minutes  and I was super nervous . I had to cut most of the important 'details' of the research methods and findings which I think make the original contribution of the paper.

Here is the result. My talk at Transforming Transportation 2018 was recorded and you can watch it below.

If you have time, I would recommend watching the whole video and check the talk by Joanna Moody (MIT), who is the other Lee Schipper awardee of 2017 and who is conducting a very interesting research on 'car pride' in different countries. The video also brings a bit more context about the Lee Schipper Memorial Scholarship. Applications to the 2018 Lee Schipper award are open, by the way.

Here are a few personal impressions on the TRB conference:
  • The TRB annual meeting is perhaps the largest academic conference on transportation, with approx 15 thousand people. And I thought the annual conference of the American Association of Geographers (AAG) was big with 9k
  • As you can imagine, the most demanded sessions at TRB were on big data, sharing economy and smart cities and all possible combinations of these topics. I am sure there must have been a session on the potentials of big data to inform the mobility sharing economy and create smarter cities
  • There were a few dozens of studies on transportation equity, multimodal accessibility analysis, socio-spatial inequalities and segregation using all sorts of data sources such as GTFS, GPS, mobile phones, social media etc. A lot of work is now being conducted in R as well. Only few studies, though, would do a good job at combing robust methods/data to a more theoretically grounded view of accessibility measures and transportation equity, including a more critical understanding of these issues.

It was a humbling experience to attend TRB and one of the takeaway lessons I took with me is this. 
  1. The academic environment is getting more competitive, with many more good scholars taking advantage of the richer data sources available out there and conducting super interesting research using cutting edge methods and open source software. The frontier is moving quickly.
  2.  Beyond the increasing challenge of getting published, it is getting harder to stand out from the crowd and write studies that will be read/cited for having a real impact within the academic community. It is easier nowadays to write good papers. It is becoming harder, however, to give an original contribution.
  3. The bright side of this story, though, it that on the technical side it is getting relatively easier to use the state of art methods/data from academic research to tackle 'real' problems, improve public policies etc  on the political and governance side things are crazier than ever, though 

Thursday, January 18, 2018

A challenge for your mental model of the world map

Here is a great exercise to test how accurate is your perception of the relative sizes of countries and continents. My score was 67% in my 1st try and 74% in my second try. Not good considering I'm doing a PhD in geography. sssh don't tell my university otherwise they might not give me my degree

This is part of a PhD research at Ghent University. ht Sebastian Meier‏

Wednesday, January 17, 2018

Following the advice of my supervisors

"Sure, it is totally doable", I said...  #truestory

many times #truestory

Friday, January 12, 2018

Data visualization of the day

Scott Kerr‏ on Twitter: "Data visualization of where I cut stuff"

image credit: Scott Kerr‏

Thanks Chico Camargo for the pointer!

Tuesday, January 9, 2018

The effects of rent control on tenants, landlords, and inequality

Good read on the effects of rent control. There are many interesting results and Damon Jones presents a very good summary and discussion in this thread.

Diamond, R., McQuade, T., & Qian, F. (2018). The Effects of Rent Control Expansion on Tenants, Landlords, and Inequality: Evidence from San Francisco. NBER Working Paper No. 24181

We exploit quasi-experimental variation in assignment of rent control to study its impacts on tenants, landlords, and the overall rental market. Leveraging new data tracking individuals’ migration, we find rent control increased renters’ probabilities of staying at their addresses by nearly 20%. Landlords treated by rent control reduced rental housing supply by 15%, causing a 5.1% city-wide rent increase. Using a dynamic, neighborhood choice model, we find rent control offered large benefits to covered tenants. Welfare losses from decreased housing supply could be mitigated if insurance against rent increases were provided as government social insurance, instead of a regulated landlord mandate.

Thursday, January 4, 2018

Sao Paulo from above in new year's eve

This video is from 2016/2017 but there are shorter ones from this year and from 2014 which also give a good idea of how Brazilians take year's eve quite seriously.

Wednesday, January 3, 2018

On my way to Washington DC

I'm flying to DC in the next few days. Thanks to the Lee Schipper Memorial Scholarship I was awarded in 2017, I am going to present part of my doctoral research at both the TRB annual meeting and Transforming Transportation. In both occasions, I will be presenting an in-progress version of the 3rd paper of my thesis, which you can read below. In case you're in DC next week and would like to grab a  coffee or beer, drop me line or a tweet.

Pereira, R. H. M., Banister, D., Schwanen, T., & Wessel, N. (2017). Distributional effects of transport policies on inequalities in access to opportunities in Rio de Janeiro. SocArXiv. doi:10.17605/OSF.IO/CGHX2. Available at

The evaluation of the social impacts of transport policies is attracting growing attention in recent years. Yet, this literature is still predominately focused on developed countries. The goal of this research is to investigate how investments in public transport networks can reshape social and geographical inequalities in access to opportunities in a developing country, using the city of Rio de Janeiro (Brazil) as a case study. Recent mega-events, including the 2014 Football World Cup and the 2016 Olympic Games, have triggered substantial investment in the city’s transport system. More recently, though, bus services in Rio have been rationalized and reduced as a response to a fiscal crisis and a drop in passenger demand, giving a unique opportunity to look at the distributional effects this cycle of investment and disinvestment have had on peoples’ access to educational and employment opportunities. Based on a before-and-after comparison of Rio’s public transport network, this study uses a spatial regression model and cluster analysis to estimate how accessibility gains vary across different income groups and areas of the city between April 2014 and March 2017. The results show that recent cuts in service levels have offset the potential benefits of newly added public transport infrastructure in Rio. Average access by public transport to jobs and public high-schools decreased approximately 4% and 6% in the period, respectively. Nonetheless, wealthier areas had on average small but statistically significant higher gains in access to schools and job opportunities than poorer areas. These findings suggest that, contrary to the official discourses of transport legacy, recent transport policies in Rio have exacerbated rather than reduced socio-spatial inequalities in access to opportunities.