The traffic light map at the intersection (pictured above) feels so troublesome. Please explain.

That box is the zero line of all equipment. Draw a 123 in the circle, which can be regarded as the positive pole. You will find that the line from 1 connects the red light in the east-west direction, the street light in the north-south direction, the yellow light in four directions and the green light in the east-west direction, and the red light in the north-south direction. In this way, at any time, only one of 123 will be turned off, and only one light in each direction will be on at any time. For example, 1 turns on the switch, the red light in the east-west direction is on, the green light in the north-south direction is on, and so on. Please accept it if you are satisfied.