Rafael H. M. Pereira 🚡 Urban Demographics

Announcing {freestiler}: a high-performance vector tiling engine for R and Python.

Generate vector tiles for your maps directly from R/Python spatial data, @duckdb queries, and local spatial files.

Check out the docs here: walker-data.com/free...

Some highlights:

The Trays, the most beautiful open office space I've seen. At the Harvard Graduate School of Design GSD

We're kicking off March with two data-driven talks, from 🏙️ cities to ⚾ baseball.
𝗥𝗮𝗳𝗮𝗲𝗹 𝗛. 𝗠. 𝗣𝗲𝗿𝗲𝗶𝗿𝗮 explores spatial accessibility and equitable urban policy.
𝗦𝗰𝗼𝘁𝘁 𝗣𝗼𝘄𝗲𝗿𝘀 applies modern stats to baseball, from pitch models to MLB pickoff strategy and bat-tracking data.
tinyurl.com/mpr87m6t

As of 2025, this analysis of privacy policies indicates that every major AI company uses your private conversations to train their models by default. Every prompt, file, photo, personal detail: all of it feeds directly into model training. arxiv.org/pdf/2509.05382

The Urban Mobility and Climate Change Conference is just around the corner (March 5 and 6). You can either attend the conference in person, or watch it live online. See registration info and full program here www.hks.harvard.edu/centers/cid/...

We live in a magical time for #dataviz. This map is just a static html page served on GitHub pages 🤯

It uses the incredible {pmtiles} #rstats package by @kylewalker.bsky.social to quickly filter through ~21M rows of data hosted on Cloudflare

vehicletrends.github.io/hhi-map/

Seeking causality in transport research Recently published * Levinson, David (2026) Seeking causality in transport research. Transportation Research Today. Volume 1, Issue 1, Article 100001. [doi] Abstract Transport policy asks causal questions, yet much transport research answers them with associative designs and then uses causal language. This Perspective (i) distinguishes causal, associational, and descriptive claims, (ii) offers a compact set of norms and a checklist for aligning claims with identification, and (iii) illustrates these ideas with examples drawn from pricing, operations, access, network evolution, and evaluation. Keywords Causality, Inference, PerspectiveFig. 1. Example causal diagram for a congestion charge, illustrating how confounding (for example, demand) and simultaneous changes (for example, fuel prices, transit service) can bias naive before–after comparisons. Colors and symbols indicate hypothesised directions.

Seeking causality in transport research

We use 30 year averages to show climatology (average weather conditions). During the 20th century the UK climatology followed a path around a confined box. With #globalwarming and #climatechange they have escaped out the box. This #dataviz shows UK rainfall and temperature.

Bluesky Map Interactive map of 3.4 million Bluesky users, visualised by their follower pattern.

I made a map of 3.4 million Bluesky users - see if you can find yourself!

bluesky-map.theo.io

I've seen some similar projects, but IMO this seems to better capture some of the fine-grained detail

Against Free Buses Much of the public discussion over A Better Billion, our proposal to increase New York’s subway construction spending by $1 billion a year in lieu of Zohran Mamdani’s free bus plan, has…

Pedestrian Observations: Against Free Buses pedestrianobservations.com/2026/02/19/a...

#statsmeme

Me aventurei na rede ao lado de fazer um react desmentindo o Kim Kataguiri.

Essa galera vive de espalhar mentiras e absurdos.

Quem quiser prestigiar. De um oi por lá também!
www.instagram.com/p/DU8ISXEjuht/

Great piece from @dsquareddigest.bsky.social, which touches on one of the big theories for why English-speaking countries do especially badly at housebuilding:

Adversarial and litigious common law systems (Anglo) vs judge-led civil law systems elsewhere.

samf.substack.com/p/build-the-...

@Eurostat published a #map showing accessibility to healthcare and education services in Europe:
link.europa.eu/TMxdbb
Explore the map: link.europa.eu/QWbyBX

#gis #cartography #gischat #demography @ec.europa.eu
@nosservicespublics.bsky.social

#r5rgui v0.2 for r5r (@urbandemog.bsky.social)
New:
- compare routes and transport modes
- compare networks! (e.g. OSM vs official streets Trafikverket.se)
- query speed
- custom basemaps (via `mapgl` @kylewalker.bsky.social )

Still in one line of code!

www.ekotov.pro/r5rgui/

#rstats #gischat

Network map of Bluesky users Theo Sanderson visualized the network of 3.4 million Bluesky users, placed by follow patterns. It is searchable and interactive. If you zoom in close enough, you can find our tiny pocket of data vi…

Network map of Bluesky users flowingdata.com/2026/02/11/n...

Very intesting-looking new literature review article on how to define minimum levels of necessary mobility doi.org/10.1016/j.er...

It's easy to feel overwhelmed by the current pace of change in technology.

A useful counterpoint:

There are STILL organizations using ArcMap for their GIS even though ArcGIS Pro has been out for over a decade.

Technology moves fast; capacity for adoption, not always.

This looks super cool

Spatial patterns of access-density mismatch reveal infrastructure gaps and strategic opportunities for new housing Recently published:

Spatial patterns of access-density mismatch reveal infrastructure gaps and strategic opportunities for new housing

📃 "Navigating the urban fringe: Socially embedded adaptation of informal transportation amid Bogotá’s urban gondola investment"

✍️ M. A. Santana Palacios

🔍 What are the dominant social dimensions that shape adaptation of informal #transportation to urban change?

📖 buff.ly/Hl9xdyF

kuzco: Computer Vision with Large Language Models Make computer vision tasks approachable in R by leveraging Large Language Models. Providing fine-tuned prompts, boilerplate functions, and input/output helpers for common computer vision workflows, su...

🚨 kuzco is now on CRAN 🚨

cran.r-project.org/web/packages...

Yes. The y axis also varies, which is not great. It would be nice to see the same chart using the same scales for all regions

Amazing chart, it tells so many different things. but overall, it suggests that raising female education reduces fertility more sharply when labour markets and social welfare systems provide less support for motherhood.
Paper: link.springer.com/content/pdf/..., via @johnholbein1.bsky.social

Imagem retirada da apresentação, com o seguinte destaque: "Nas condições observadas, a Faixa Azul não se configura como uma política de segurança viária"

Publicada hoje a primeira pesquisa científica e independente sobre as Motofaixas de SP!

Nunes transformou a ideia fraca em marketing político muito antes dela ser comprovada.

A pesquisa mostrou que elas aumentam a velocidade e com isso o risco de mortes, e aumentaram as mortes no trânsito!

It's 2024 5-year American Community Survey release day!

The ACS is the best resource for small-area analysis of US demographics.

In R, use tidycensus and mapgl to dive into the data right now.

Copy-paste the code below for an interactive income map with a legend filter:

Free Buses? How About Expanding the Subway by 41 Miles Instead?

41 miles of new subway for the cost of free buses. Here’s an audacious, expansive plan to expand the subway’s reach & catalyze housing to attack the affordability crisis. An incredible effort from NYU Marron team. Excited for this to be out in the world:

www.nytimes.com/2026/01/30/n...

Live Free and Die: US Life Expectancy Has a Problem (But It's Not Seed Oils) We deserve to live until we are old

We deserve to live until we are old.

substack.com/home/post/p-... #publichealth #demography #epidemiology #healthpolicy

Headshot of Nancy Fraser, Senior Loeb Scholar, smiling.

👏 Congratulations to political philosopher Nancy Fraser, the Spring 2026 Senior Loeb Scholar! Senior Loeb Scholars spend time on campus, during which time they present a public lecture and engage directly with GSD students, faculty, staff, researchers, and Loeb Fellows.

https://hgsd.us/4a0NN7g