We have them in some suburbs here in Montreal. I believe they are quite common... nothing novel as such.

I don´t know about Montreal but here in Costa Rica (Central America) as you can imagine, that timer would be very helpful, for pedestrians also. Here, when you walk and get to the corner, you see the red light on, so you walk but if it changes to green while you are crossing... wow, you better run!!!

Forgive me for disagreeing. Especially in New York. There are laws against honking your horn. If a driver can't wait until the light changes, there maybe an issue there. The whole purpose of the "yellow" light is to signal drivers the light is about to change to red. As for pedestrians in New York, the "Walk" and "Don't Walk" signals already "flash" about 10 times to give people warning that it is about to change. I get a kick out of this one. Because when I see people who have just stopped at a crosswalk because the "Don't Walk" signal started flashing, I start walking slowing across the cross walk counting the flashes. Unfortunately, some people look at me from behind and also start walking across as slow as I do. By the time I get to the other side, the light changes and these people are running for their lives. The light will even let you know when it's the last "flash" by "double" flashing at the end.