A dead-head is when part of a transportation trip has no cargo moved within it. For example, when a truck goes from Nashville to Minneapolis with guitars, but it comes back to Nashville empty; that is a dead-head trip. This happens because of supply and demand; there might be more demand out of China than bringing more products into China. Thus, there will be a lot of dead-head trips back to China to have containers to ship things out of China. Ideally, products coming out would be equal to products coming in for environmental and financial reasons, but often this is not the case.