I've ran this question across a couple of forums but still don't fully understand what they are / how they work. Maybe Roger or someone else can advise.

I noticed on my recent visit that there were small blue lights above the traffic signals at several junctions.

What are they for ?

Some have said that they red light cameras, some that they only indicate when the light has turned red so police can see if you have passed through one. Also they are an indication to emergency vehicles which way the lights are sitting.

BTW I'm confident that I have not ran any lights so I'm not asking this question because of that. Just curious and would be useful for those about to visit.

Thanks,