Citibike Explorer is a dashboard for visualizing Citibike’s published ride history dataset.

The project mostly stemmed from my desire to play with sql.js-httpvfs, a library for streaming statically hosted SQLite databases into the browser. I also found myself playing with Citibike data quite a bit and wanted to write a simple utility for fetching, storing, and transforming the dataset.

Overall I’d say the project has been a success. I’ve confirmed that sqlite.js-httpvfs is a pretty powerful tool for querying large read-only datasets without needing to spend time building a backend service. I was most impressed by its performance when rolling-up 10 years of hourly data into daily and monthly resolutions- that’s all happening in your browser!

This project also resulted in publishing Citibike system data reference, something I should have done a long time ago given how many times I’ve sat around scratching my head while working with these trip history archives.

As of now Citibike Explorer only allows for visualizing trip volume over time, but in the future I’d like to mess around with scraping and visualizing the realtime feed of station data. Perhaps that can be my excuse to try playing with Protomaps 😬.

Notes and prior art

• ctbk.dev is another Citibike dashboard that is more feature complete than my own.
• A friend recommended trying to implement this using DuckDB, which seems like it could be conducive to this sort of data analysis. They even have a wasm implementation!