This is such a minor nitpick, but I'm bothered by it because I see so much performance-shaming coming from some Googlers:

The site loads large pictures for all viewport widths (ideally they'd load downscaled images for smaller viewports — it's wasteful to load a large image for small devices) and the image files are PNGs when they should be jpeg or webp (example: http://waymo.com/static/images/journey/streets.png)