Ro-ro refers to 'roll on / roll off'. This name explains how the cargo is discharged and loaded. This concerns cargo that can be driven which is only done by especially trained drivers. Ro-ro is used for cars, busses, trucks, agricultural vehicles and cranes. To transport as many of these vehicles in one go, enormous ro-ro vessels have been built. Some ro-ro vessels have enough room for more than 8,500 cars!