Or ‘drive-through’ racking. This system enables pallets to be stored one behind each other in racking, thus saving aisle width. New pallets can be added at the back of the row, pushing the existing pallets forward on tracking within the racking. This would be used for the same product and allows a FIFO (first in first out) system to be run. Roll in roll out is suitable for relatively fast moving whole, full pallet in full pallet out, product.