If the terminal is really slow the first thing a shipping like will leave behind is empty containers. US terminals are dead slow and often do not work 24/7. The

If the terminal is really slow the first thing a shipping like will leave behind is empty containers. US terminals are dead slow and often do not work 24/7. Their union is unique, it seems to be a show of power instead of making sensible decisions. There's a huge backlog of vessels that need to be handled. Usually you have space on the vessel to bring back the empties, normally the reason not to do that is if it takes too much time to bring them on board (terminal is slow or vessel was late). If it was due to too many vessels it could've been solved by sending a vessel purely for empties. But there's a huge backlog in vessels to be handled. Productivity increases usually take quite a while to materialize.