This is such a unique trolleybus system! For most trolleybus systems, there is only one direction for each lane, but at here, the trolleybuses go both ways in one lane, just like a single-track railway. So trolleybuses here are able to rectify the current (so no worry about the position of the positive and negative wire) What's more, the catenary wire parts are interesting too. For normal trolleybus catenary wire systems, merge switch frogs cannot be used in the opposite direction, they can only be used when two lanes merge together. But for this system, the switch frog is similar to a railway spring switch, so it can be used at both ways. (Trolleybuses coming from the reversed direction always go straight, they won't go to the side direction)