I was there in 2008 when I attended a conference near Taksim square. However, this was during Ramazan - so maybe traffic during Ramazan is worse then during the remainder of the year.
When I was there most crossings looked somewhat like this (warning: terrible video quality): http://www.youtube.com/watch?v=0cYdHUmG100 (I had a green light when I passed this crossing as a pedestrian).
When I was there most crossings looked somewhat like this (warning: terrible video quality): http://www.youtube.com/watch?v=0cYdHUmG100 (I had a green light when I passed this crossing as a pedestrian).