We are talking a 500k people city, purple are the only roads where 50 is still the limit, rest of yellow is all 30 (i repeat: 18 mph).
If i had described this possible outcome 10 years ago as one of the many reasons the left is a threat to humanity, i would have been called a conspiracy theorist and so on.
Now it's law and we can manage only because we have a strong internal sense of spite of insane laws, so we mostly simply disregard them. That includes public bus drivers who , if they followed the limits, couldn't actually do their job following time tables.