Source: BTS.
Value Per Ton of U.S. Freight Shipments by Transportation Mode, 2002
When transportation systems are taken individually they carry commodities in accordance to standard transport economics; the value of what is being transported is related to the transport costs of the mode being used. Commodities strictly carried by rail have the lowest value per ton (e.g. coal, gain) while those carried by trucks tend to have a higher value. It is not surprising to see that parcels shipments and, finally, air transport shipments have the highest value per ton. The freight been carried by air transport is about 450 times more valuable than the freight carried by rail and 115 times more valuable than the freight carried by truck. Air freight tends to involve high value goods such as electronics and pharmaceutical products.
When modes are used in combination the situation changes significantly and the freight carried is much more valuable than what is been individually carried on any of the concerned modes. For instance, the value of freight carried by a truck and rail combination is 7 times more valuable than rail only and twice as valuable than truck only. From a system-wide perspective, the value of commodities carried on multiple modes is 8 times as much as those carried on single modes. This is an indication that intermodal freight transportation concerns specific commodity chains, more sophisticated products carried over longer distances (often internationally) as well as the potential added value conferred by intermodal transshipment.