I'm in Southwestern Connecticut. I'm not sure that there are such roads around here. The terrain is all glacial tailings, so valleys tend to run exclusively north/south. Main power grid lines tend to run east/west as the generating plants are in the middle or eastern part of the state. So the terrain under power lines is quite steep and there aren't really roads to service the pole lines like there are in the Midwest or the West. Instead, they tend to have access to each individual pole by a stub road from a different street as the power line goes up the hill. The hills are too steep to run a bucket truck up or down.
I can't speak to what you might find in other parts of southern New England.