Hi,
We can use state machine in order to schedule the Led timing for each trafic light.
Just Let me know your wiring diagram, and let's finish this project together.
I have became firmware engineer since 2012 and I have built similar project before back in 2010 for my Senior High School final projects, but instead using arduino, I use PLC.
Lets discuss this project over messenger, and let me help you finish it.
Best Regards,
Rijal