Green Energy

Much like the OP, doing solar in long strips like you would have to for cycling path presents some issues when it comes to the supporting electrical equipment, a square parking lot is a lot more condusive to it. As for tram stations, sure you could easily enough power it with panels but to be feeding into the grid with such a small amount of panels/station is probably not going to be cost effective (again) when it comes to the supporting equipment, especially when it's right next to limitless power from the train lines.