Hey Guys I found This MOC Someone Made under name of "camlegofun" who made a great simple Lighted signal! I was unable to get the picture but you can see his/her work at LEGOIdeas: https://ideas.lego.com/projects/71391
Maybe we can make this become a reality?
Just thought it would be good to share it, Rail Co
Update: He has updated the page explaining it better and even a V2 design.