LA’s Synchronized Traffic Lights

Los Angeles has synchronized every traffic light in the city:

Without synchronization, it takes an average of 20 minutes to drive five miles on Los Angeles streets; with synchronization, it has fallen to 17.2 minutes, the city says. And the average speed on the city’s streets is now 17.3 miles per hour, up from 15 m.p.h. without synchronized lights.

It doesn’t seem like much gain but these are just the average numbers. I imagine there are parts of the city that have significantly improved.