Thenbsptraffic signalnbspfor the main street gets highest

Question

The traffic signal for the main street gets highest priority because car are continuously present on the main street. Thus, the main street signal remains green by default.

Occasionally, cars from the side street arrive at the traffic signal. The traffic signal for the side street must turn green only long enough to let the cars on the side street go.

As soon as there are no cars on the side street, the side street traffic signal turns yellow and then red and the traffic signal on the main street turns green again.

There is a sensor to detect cars waiting on the side street. The sensor sends a signal X as input to the controller. X = 1 if there are cars on the side street; otherwise, X = 0.

There are delays on transitions from S1 to S2, from S2 to S3, and from S4 to S0. The delays must be controllable.