The approach utilises a simultaneous equations system to derive a discrete/continuous choice model for the choices of mode and shipment size in the intercity freight market. The method is applied to the demand for intercity freight transport using data from the US Census of transportation.

Distribution has largely passed from control by the supplier to control by the retailer, and from own-account to contract operation. Improvements in the road network should make journey times more predictable. The “business potential” gained from the road improvements is often much larger than the time saved.

Since rail rates in the US were partially deregulated, they have been affected more strongly by competition and less by costs. The strength of competition from trucks depends on fuel prices and improvements in technology, and, on the demand side, on the availability of rail cars.