简单的交通灯程序。一般情况下（初始状态），干线亮绿灯，支线亮红灯。当支线上有三辆车到达路口（用按键按下模拟一辆车到达），则6秒后，干线亮黄灯，持续3秒后，转为干线亮红灯，支线亮绿灯，过24秒后，支线转黄灯亮，3秒后，回到初始状态。-Simple procedures for traffic lights. Under normal circumstances (initial state), the route a green light, red Extension. When the extension has three cars reach the intersection (by pressing the analog button to reach a car), then 6 seconds, the route bright yellow, sustained three seconds later, to Route red, green light Extension lead 24 seconds after the , Extension turn yellow light, 3 seconds later, return to the initial state.