延米（或）是一个虚拟的量度单位，原用于运输业，以将货物的长度换算为所佔地的面积。根据美国北卡罗来纳大学系统的"How Many? A Dictionary of Units of Measurement"对""的定义为："A unit of deck area for "roll on/roll off" ships: cargo vessels designed so that containers or other cargo can be rolled on and off the decks o