Methods of storage and/or retrieval of items from storage racks using carts include electronically determining a size of an item and determining a storage position in a row for the item based on the determined size. The size can be determined by reading indicia on the item and consulting a database to determine a size of the item based on the read indicia. Other methods include electronically determining a characteristic of an item and determining a load movement limit protocol for the item based on the determined characteristic. The protocol may limit velocity or acceleration of movement of the item.