That is the worst waffle iron I have ever seen.
I puzzled over the fact that the Castro was nearly the same color as Sunset, until I realized that I had misunderstood the title.
Market street is straight until it gets to Castro.
Ha! Gay jokes! When's the next Peterson & Bell open mic?
A glance at these maps (combined with driving experience in all but Tokyo) makes me think that the algorithm reveals most clearly how easy it is to get lost driving in each city.
Or even walking! The Paris one matches my memory of trying to get to the Eiffel Tower by dead reckoning (you can see the damn thing for miles) and having a really hard time actually getting there because none of the streets go in a sensible direction.
US cities are so weird. It's like the roads aren't based on the route some farmer used to take their cows down to the river two thousand years ago. Crazy.
After looking at those, I'd love to see two other maps: one that indicates average of curvature of streets, and another that shows connectivity (so a tree structured neighborhood of cul-de-sacs and boulevards would be one color, and a completely connected rectangular grid would be a contrasting color).
I've seen the second, it's fascinating! There's nothing quite like quantifying all the city's bottlenecks at once to give you a sense of the scale of traffic problems. Most residents intuitively know what's on that map, but seeing it all together really makes you rethink all your supposed solutions to "traffic these days."