Show HN: Visualizing Eclipse Traffic Impact in Vermont

Hello! Long time lurker, first time poster.

I’ve always been fascinated by maps and how they can track and reflect our lived experiences. The eclipse coming to my town was a perfect opportunity to use a map to demonstrate the magnitude of the impact of crowds of people descending on our little state.

I wanted to visualize this impact in an informative and visually appealing way. being a regional hotspot for viewing the totality, I was curious about the eclipse's effects on traffic. Map apps only show you the "now," and that was not what I wanted, so I decided to take matters into my own hands.

After reviewing various traffic data providers, I settled on using TomTom. Their policy on data usage was a crucial factor, as many providers restrict scraping. TomTom's Flow/Relative raster tiles offered the perfect balance between clarity and detail, emphasizing traffic conditions with a transparent background, perfect for overlaying standard basemaps.

I developed a script to programmatically scrape the tiles in my region across a few zoom levels, trying to balance TomTom's costs and limits with the desired level of detail and storage costs. I set up GitHub actions to run the script at regular intervals throughout the day leading up to the eclipse and then extra times on the day of.

I initially stored the files directly in GitHub, but that quickly became unwieldy and led to 429 rate limit errors. I then tacked on a "Copy to S3" step to get the data out of the repo and set up CloudFront to improve performance and limit transfer costs.

AI, particularly ChatGPT and GitHub CoPilot, played a significant role in developing this project. Each line of code, while initially drafted by AI, underwent thorough review and refinement by me. This blend of AI efficiency and human oversight was essential, especially given the occasional need to correct or redirect the AI's approach. (I let ChatGPT write this paragraph and present it without editing)

I hope you enjoy exploring my simple little map! Take a close look at totality (3:32 period), then immediately afterward (4:02 period). The map lights up red!

Then, watch as the huge flow of traffic heads southward. I heard anecdotes of it taking 2-3x as long to get home!