In China, buses are not only used to transport people, but also to move cargo. The top of the bus is considered nothing more than a large storage deck, so why not make some extra money and charge to carry cargo as well? I am amazed by how high workers can stack cargo on a bus, and I am equally impressed by how skilled the workers are in securing the cargo with heavy nets.
Honestly, I have seen a bus or two that had such high stacks of cargo on them that I had no idea of how they kept from rolling over. I would think the weight distribution is critical for a bus loaded with cargo, and they would have to watch for low overpasses!
In the rural areas, the bus may make several unscheduled stops to pick up passengers. The people will sit beside the road and wait for the bus to come by.
When the new passengers are loaded on the bus, their cargo has to be secured. I once saw someone shipping glass windows on a bus. To my surprise, I heard they made it just fine.
If you ever have the opportunity to travel in China, I would like to encourage you to take a bus……just one time! You will be exposed to a common mode of transportation for most people, and you will get to meet many nice people. Sure, they will look at you funny initially, but then they will become your friend.