Red,stop; Green, Go; Yellow, slow!
My toddler's familiarity with traffic lights began when he watched hi-5's educational song about cars and hi-ways and whenever we go out he actively tell daddy what light is on. We have bought toys of different vehicle types to build his own hi-way and play car race. We even play car games online aside from his fave Ben10 Omnitrix unleashed!
Whew... I'm really having a hard time coping with boy's kind of games so when daddy is here I let him do all the assistance in playing games like this for he knows best when it comes to car racing; unlike me that only enjoys "Pimp Fashion rides" giving a fashionable look experimenting on car's new styles and designs. =)