Bjarney,
I'd agree with you on the fusing of street-lights, over here we use HRC fusing in each standard.
Hotline,
Using GFI protection on Line equipment would, to a certain extent, be a waste of time and money, in that, Insulators, by their virtue, attract dust during dry spells, when the air moisture level increases, this dust becomes damp and you have an instant tracking problem, that can cause a small leakage current to Earth, via cross-arms(wooden or metallic).
Even at Low Voltage, this can be a real problem. [Linked Image]