Many happy returns to the Romanian Police! We marked the day by turning into little officers and learning the rules of the road.
Road safety rules are among the few things taught at after school that get used the very same day, on the way home. That is why we take them seriously: where to cross, what each traffic light colour means, why you stop and look even when you have a green light.
Role play helps more than it seems. The child directing the traffic has to know the rule in order to apply it to others — and that fixes it far better than merely having listened to it.