Do demurrage and detention (D&D) fees help or hinder efforts to untangle the supply chain at America’s seaports? D&D fees are assessed by MTOs—marine terminal operators and “common carriers,” meaning vessel operating common carriers (VOCCs) and non-vessel operating common carriers. (NVOCCs). The fees have a straightforward intent: pick up and return your stuff on time or you will pay extra, a notion that most people support. To distinguish: Demurrage is charged daily by the shipping line from the date of discharge until the container is moved out of the port, while detention is charged per day per container by a…