[wffurr]

There's some interesting HTML comments in the source.

"ai2html" sounds like the source is Adobe Illustrator and probably refers to this tool: https://github.com/newsdev/ai2html

Not sure what "freebird" is, some internal software. I can't find much about it with Google search.

    <!-- data processed in process/freebird/process-graphic.js -->
    <!-- asset wrapper : start -->
    <!-- ASSET : START -->
    <div class="g-asset g-graphic" style="max-width: 945px">
    <!-- Intro elements -->
    <!-- inner graphic element -->
    <!-- print .html file -->
    <!-- Generated by ai2html v0.100.0 - 2020-03-22 00:19 -->
    <!-- ai file: maps_la.ai -->
    <!-- preview: 2020-03-19-coronavirus-us-cities-shutdown -->
    <!-- scoop: coronavirus-usa-traffic -->

[v8engine]

Yup. ai2html seems to what I was looking for. Didn't spot that because of all the freebird comments.

As for freebird, my search led me to this. https://github.com/freebirdjs/freebird

Seems to be the NYT has an array of pollution sensor IOT across the cities and they are using Freebird to control them. Just my guess.