If you prompt an LLM to Shine on the GTFS…

I’m testing out how LLM chats can improve my workflow.

The other day (from several weeks ago) I went over to Claude and asked them to write a Shiny App that allows the user to upload a GTFS zip file and explore the transit system described within the upload. This is the result. I haven’t edited it really, just wanted to see what kind of output we get here. I think it’s pretty neat.

I moved to Washington, D.C. over three years ago to accept a inaugural position of Transit & Rail Data Scientist at an engineering and public transportation consultancy firm. The General Transit Feed Specification (GTFS) featured prominently in my day-to-day work; it is a standardized mapping (through data) of the operations of a transit agency. You can find further documentation of the GTFS here.

This app offers the user the chance to upload a GTFS zip file. They used to be easier to obtain and download from reputable sources, but now you must create accounts with these websites and thus jump through some hoops. I found this link that allows us to download the Metrorail GTFS fof the Washington Metropolitan Area Transit Authority (WMATA). Make sure you click on the link that says “Latest GTFS Feed - Corrected & Enriched”.

Once you’ve downloaded the zip file, proceed with uploaded that zip file into this app, and give it a shot at trying to understand what goes on inside the GTFS :)