One time in school we had to do project with micro-controller ant I have programmed traffic light in C and for presentation have done this presentation PCB. In one side of BCP is circuit and in other side is imitation of traffic road with traffic light maded with LED.
First we have to etch PCB board. This PCB have been done by laminator process (It's described in project category).
I have used double sided FR4 PCB. At the other side of PCB I etched imitation of traffic crossroad. We have to slightly drill over holes of LED, just to make sure that there wont be any short circuit.
For protection against copper corrosion I soldered all surfaces, you can also use plastic spray (I didn't have it that time). The exposed copper is defending himself against with oxides and is good to protect him.
Finished model of crossroad with traffic light
Here you can see finished crossroad with traffic light that is attached to the breadboard and connected to the micro-controller with program in C. Below this you can find video from my YouTube channel.
Here you can see how the model works. Don't forget to subscribe on my YouTube channel for more random tutorials!