Anecdotal but London seems to have a reasonably 'smart' traffic light system. It's something you only really notice when you're looking out for it (sign of a good system?), but as a pedestrian it's very often that pedestrian crossing phases match extended gaps in traffic flow. On roads with a good sightline, I often notice a gap in the flow ~30 seconds away that the lights will change in sync with.

The system is called SCOOT if you are interested.