Typically, there are 4 traffic light poles at a crossroads. The master is fixed with one of them or fixed in a ground waterproof carbinet.
The master releases radio-frequency signal to each slave that is embedded in its own traffic light group, thus controls each light on-off.
Essential Parts
6-38V 4-220A battery can be customized per your traffic light controller.
0.5-280W solar panel can be tailored to your traffic light controller.
Every traffic light group should install one slave to receive RF signal from master.
In each light group, a slave is fixed on the back side of one traffic light.
The master should be fixed in a waterproof carbinet.
This waterproof carbinet can be fixed on traffic light pole or installed on the ground.