While driving out of country recently, I came across a number of signalized intersections on major collector roads that had an illuminated blue light facing the opposite direction of the main signals. Here’s a picture, taken a night so the blue light shows up:

this is a multiple lane major road crossing another at signalized intersection, much like say Hunt Club Road at Merivale or Woodroffe at Baseline. The signal heads in the above pic are for the opposing direction of traffic, but some heads have a bright blue LED light shining the opposite way.

I am guessing here, that they might  signal police or emergency vehicles when the opposing traffic flow has or hasn’t a green, to facilitate a cross-traffic turn by the viewer. But if this was the case, then yahoos would figure this out and use it for high risk light jumping.

I didn’t see these very often, just enough to notice them, but I wasn’t through enough intersections to determine a pattern. Does any reader know how these work?