I was always fascinated by traffic lights so I decided to build a model for my own.
The first idea was that I would glue in traffic lights made from straws to hardboard and wire this up using aluminium foil. I realized shortly that I wanted to upgrade this to 2 traffic lights per road and that the aluminium foil teared very often.
So I completely removed the aluminium foil and its attachments points and used a very thick wire instead. It was a very thick one. So I removed the wires too.
The third iteration used white PVC instead of hardboard, so I could draw the road on the plastic. I measured everything precisely and used good wires. I also added pederstian signals. This is the end result.