Earlier this summer, Google Maps started displaying traffic lights for some users. Although that appeared to be an experimental feature, as none of us at AndroidPolice could get them to show up, they're finally rolling out widely.
Google seems to have rolled out the feature overnight to a wide range of users, if not all, as traffic light icons are now showing up on Google Maps. The functionality doesn't need to be turned on manually and doesn't require you to activate traffic layers as we initially thought.
It doesn't look like there's been an evolution since the trial rollout, as the icons look the same and automatically adapt to the map size. They appear both when browsing the map or navigating, giving you a handy indication of why traffic might be slowing up in front of you.
Sadly, I've only been able to see them in the US, and couldn't get them to show up in France or Canada. We'll hopefully get to see these in more countries soon, as Google definitely knows where most lights are located anyway.