I spotted this detail alongside a country road in central Illinois, and again near Springfield. It's the first time I have seen this. Each of the three conductors in the lower voltage circuit has a number of wires wrapped around it, near mid-span. I'm guessing that they act as dampeners, to prevent oscillation of the wires in the wind.

Maybe they are a less-expensive alternative to the dumbbell-shaped dampeners frequently seen attached to the cable a few feet from the insulators?