Flashing green means that the crossing traffic has a stop sign (or a
flashing red, which is the same) instead of a red light. You still have
right of way but you can expect cars coming out of the side streets
turning left or right.
At some intersections there are no lights at all for the crossing
traffic, just a stop sign. At others, most of the time the lights will
stay in this mode on the main street and would change to red only if
there's a real backup on the cross streets.

-Milen


Robert M. Gary wrote:
I just flew my Mooney up to Vancouver (this is somewhat aviation
related). When I got there I noticed that sometimes the traffic lights
were just green and other times they were flashing green. I asked many
locals what the difference was and none of them knew. Some thought it
was related to the crosswalks but I noted no cooreleation between an
intersection having a crosswalk or having someone pushing the walk
button and the flashing. Perhaps I'm just being a nerdy engineer but
I'm really curious if anyone in Canada knows what this means.

-Robert