The traffic light control system with four driving ways and one lane on each side, provided safety considerations. Let $D$ be the safe distance for a car to press brake pedal, if a car breaks in a shorter distance than D$,$ there is the possibility to cross the red light. A car needs to stop before the sign of $52,54,56,58($see the figure below$).$ In the following figure, the circle with $3$ dots represents a traffic light. The dash line splits the road for two driving directions N$-$S$,$ S$-$N$,$ and E$-$W$,$ W$-$E$.$ Twofundamental rules:

a$.$ Each car must stop at or before the sign of $S2,S4,S6,$ or $S8$ when red lights.

b$.$ In addition, a car making a turn cannot hit or collide any other car$($s$),$ no matter other car is moving or stops.

Your task is to:

Develop a class model of the system using the correct UML notation.

Design a state diagram of the system using correct UML notation.

point out weaknesses of the system, and describe how the system cpuld be improved to be more safe.