Introduction - If you have any usage issues, please Google them yourself
Traffic lights show there are many ways, such as intersections, T-junction, etc., and for the same intersection there are a lot of different display requirements, such as crossroads, if the car as long as the north-south direction and pass something very simple, but if the car can be left and right turning traffic is more complex, the present experiment only for the simplest of north-south and east-west straight.