We are actually in the process of removing our 4kv stations and either running 13.8kv or 23kv primary to residental neighborhoods. There is actually 35kv distribution lines in New Hampshire.
SCE is converting a lot of primary distribution from 4 to 12 and 16kV. I have seen some SCE 33kV to 120/240 transformers, and LADWP has a lot of 34.5kV to 120/208V and 277/480V for large services.
Yes, the higher the voltage, the less current you have on the conductor. Also, higher voltages can run greater distances and cover more area eliminating many 4kv stations and cost to maintain all the equipment associated with the stations.
From a quick search on Google, it seems Toronto still has some 4kV lines up. My best guess is they're the lines on the really old poles with wooden crossarms.
They seem to be in the progress of converting the 4kV lines to 13.8kV though.
They seem to be in the progress of converting the 4kV lines to 13.8kV though.