What are the laws about riding in the back of a pick-up truck in Georgia?

If you are under the age of 18 and in the cab of the truck, you are required to wear a seat belt. It is only illegal to ride in the back of a pick up truck if you are under the age of 18 AND on an interstate highway. It is not illegal for a 16 year old to ride in the back of a pickup truck as long as you are not on an interstate highway.