Commodity Chains and Types of Transported Freight
There is a direct relationship between the nature of commodity
chains and how freight transportation systems are organized. The
above figure provides hypothetical transport systems for the three
stages of production:
- Raw materials. At this stage, most raw materials are
going through three major processes. The first, extraction,
is the process of gathering (harvesting, drilling, mining, cutting,
depending on the nature of the material) raw materials. The second,
transfer, is the process of collecting and storing large
quantities of bulk freight, which mainly takes place at port and/or
rail terminals. The third, processing, is the transformation
of raw materials to components that can be used for manufacturing.
Processing activities tend to be closer to markets. For this stage,
transportation modes and infrastructures tend to be specialized
and of high capacity (tanker ships, pipelines, mineral or cereal
bulk carriers, etc.) since economies of scale is a strong driving
force. Intra-industrial linkages are related to an enterprise seeking
vertical integration. For instance, a steel mill (processing) could
be involved in iron and coal mining, as well as owning the transportation
modes supporting its activities.
- Semi-finished products. This stage is strictly involved
in the manufacturing and assembly of parts and products.
Depending on the complexity of the product an elaborate set of linkages
and their associated flows takes place between several enterprises.
Intra-industrial linkages tend to be horizontal as an enterprise
seeks to control most of the stages in the manufacturing of a product
or a group of products. The usage of transportation modes varies
according to the products, ranging from air freight for high value
goods to containerized or pallets traffic for parts. Globalization
has radically modified this stage with the opportunity to use new
manufacturing and assembly opportunities at low cost locations.
- Manufactured goods. This stage is concerned by the distribution
of finished products to consumption markets. The first process,
distribution, involves issues such as packaging, warehousing
and transporting products to the market, which brings the second
process, retailing. Retailing is commonly the final stage
of a commodity chain where consumers (individuals and enterprises
alike) have access to a product. For most retailing activities,
the consumer is responsible to transport the product, once acquired,
to its place of consumption but several retailers are also involved
in deliveries. Most flows tend to be regional in scale, except for
flows between distribution centers. Considering that a significant
share of the consumption takes place in urban areas, distribution
and retailing flows are increasingly an urban transportation problem.
As such, trucking tends to be the dominant mode of the process of
distribution. E-commerce has often helped the processes of distribution
and retailing to merge in a single function.