Here I go again.
Now I knew that emergency vehicles have a way to make traffic lights change to allow them to traverse managed intersections but I really never had seen it happen.
Then I did.
That is called line of sight traffic signal preemption.
Watch that video in HD. Slow it down to 1/4 speed. The preemption light is the bright white light above and to the right of the middle signal light. It comes on just before 4 seconds in. At that time, the signal begins cycling the cross traffic to orange and then red. At about 10 seconds the signal turns green for the ambulance.
Isn't that cool?