The cheapest form of freight transportation typically depends on the specific needs of the shipment, including factors such as weight, size, distance, and time sensitivity. Generally, ocean freight is considered the most cost-effective for international shipping of large, heavy, or bulky items over long distances. It offers lower rates due to the capacity to move large volumes of goods. For domestic transport or shorter distances, rail and trucking can be more economical, especially for medium-sized shipments. Air freight is usually the most expensive option, though it’s the fastest. For smaller shipments, LTL (Less Than Truckload) shipping offers a balance of cost-efficiency and speed, as it allows for sharing transportation costs with other shippers.