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.