Friday, May 31, 2019

More evidence on the health benefits of active transport

“Women who averaged approx. 4400 steps/d had significantly lower mortality rates [..] compared with the least active women who took approx. 2700 steps/d; as more steps per day were accrued, mortality rates progressively decreased before leveling at approximately 7500 steps/d.”

This is from a new paper that just came out in JAMA (via Eric Topol). And yes, the authors are have addressed reverse causation bias. Read the methods section.



Fig. Dose-Response Association Between Mean Steps per Day and All-Cause Mortality



Wednesday, May 29, 2019

My presentation at the 2019 ITF Summit

shameless self-promotion post  again 


Last week I was attending the 2019 International Transport Forum Summit, where I presented a paper on estimating the future accessibility impacts of transport project scenarios. The study also discusses the equity implications of travel-time threshold choice in cumulative opportunity metrics. Such a sexy topic, ah.

My presentation was recorded and you can watch it here (in case you really need to procrastinate on the work you should be doing now).


Monday, May 27, 2019

How congestion pricing works in London and how it could soon work in NYC

New York city is closer than ever to adopt congestion pricing. This could be a major change in how they address their transportation challenges and fund public transport. A team at Vox made an informative video about this, and they asked the sharp Nicole Badstuber (Twitter) to explain how congestion pricing works in London. London started charging private vehicles to enter the city center in 2003. Last month they enacted the London’s ultra-low emission zone, which adds another charge for most vehicles manufactured before 2015.




Saturday, May 18, 2019

Biographical note: ITF/OECD award


Hi all. I am so glad to share that I have been honored with the 2019 Young Researcher of the Year Award, by the International Transport Forum (ITF/OECD). As I've said many times, this award speaks volumes about the generous guidance and support I have received from supervisors and colleagues at both Oxford and Ipea to conduct my research. Special thanks to my incredibly  demanding  supportive supervisors Tim Schwanen and David Banister. Thanks!

This is the award-winning paper, where I investigate the future impacts that different scenarios of a major BRT in Rio de Janeiro could have on access to employment opportunities for different income groups. The study also shows that the the equity assessment of transport projects based on accessibility estimates using cumulative opportunity measures with a single time threshold (the most common practice adopted by academic studies and transport agencies) can lead to misleading or partial conclusions. The preprint of the study is available for download here (it includes a spatial regression analysis that didn't make it into the paper because or reviewer #2).

Thanks to the award, I'll be attending the 2019 International Transport Forum Summit in Leipzig next week. The team at ITF will be Twitting about the Summit. I'll be presenting the paper on May 23rd at  5:15pm (local time). Apparently, it will be webcasted on Facebook Live.

Wednesday, May 8, 2019

The reasons two variables can be correlated

A concise illustration, by Thomas Lumley. This reminded me of this quite comprehensive list of some  ridiculous  spurious correlations.


image credit: Thomas Lumley

Friday, May 3, 2019

R Links


  1. The ipumsr package helps import census and survey data from around the world integrated across time and space. I've mentioned IPUMS in the blog before. This is certainly among the most important, ambitious and succeeded open data projects in the world

  2. A rather comphrensive comparison between data.table and dplyr syntaxes and funcitonalities ht via Mara Averick. I have to say I a strong preference for data.table because of computational performance. I also generally find the data.table syntax more easily readable than dplyr. There, I said.

  3. Free Book with code: “Spatio-Temporal Statistics with R,” by Christopher K. Wikle, Andrew Zammit-Mangion, and Noel Cressie

  4. brickr: a package to Build 3D LEGO models in R, by Ryan Timpe

  5. trackeR: a package for handling running and cycling data from GPS-enabled tracking devices, by Hannah Frick

  6. A Cheat Sheet on how to use the Reticulate package for interoperability between Python and R

  7. How to create a gif of a spinning globe using R, by James Cheshire

  8. The R package traveltime allows one to retrieve travel-time information from the Traveltime Platform API to create isochrone maps like these below. Great work by Thomas Russo.


image credit: Thomas Russo

Off to Sweden

Professor Sonia Yeh (Twitter) was awarded with the HÃ¥kan Frisingers scholarship for her innovative research on sustainable transport and energy systems. The award is given by the Volvo Research and Educational Foundations (VREF) and the award ceremony will be held next week on May 6 in Gothenburg. Sonia has kindly invited Yusak Susilo and I to join her in the ceremony to celebrate her work and to deliver a public lecture. The program of the event is available here. We will also have a more academic oriented seminar at Chalmers University on May 7 in the morning, for those around. I'll be mostly talking about future directions on accessibility and equity concerns in transport research and policy. Needless to say I am very glad for Sonia's well deserved award and honored by her invitation.

After that I'll be joining some colleagues from Lund University to deliver a seminar at the The Swedish Knowledge Centre for Public Transport (K2) on May 10 at 9h20. We'll be talking about Transport Justice Perspectives: Comparing Calculated and Perceived Accessibility. Pop in if you're in the neighbourhood.