D5 Annex report WP 3: ETIS Database methodology ... - ETIS plus

D5 Annex WP 3: DATABASE METHODOLOGY AND DATABASE USER
MANUAL – FREIGHT TRANSPORT DEMAND
Introduction
As already mentioned one of the major gaps in freight data availability is the freight OD­matrix.
Within several projects (for instance INFOSTAT, CONERTO, MESUDEMO, INFREDAT) it
has been identified that it is important to consider a transport chain structure in the freight
database including transhipment of transport flows between modes and other characteristics.
Before describing how the freight OD transport chain database should be constructed, the
difficulties being encountered first are being discussed in a broader context in this chapter. This
is a general theoretical analysis of transport chain data without looking at availability of sources.
From the analysis in this chapter questions evolve that need to be answered within ETIS in the
light of (inter­modal) freight transport. First some basic concepts are being discussed after
which the characteristics of transport chain are described. Eventually some words are being said
on the level of detail and concluding remarks are given.
Transport chains
The transport Chain Concept
In most databases a strict distinction is made between trade and transport databases. In trade
databases the commodity flows are described from origin to destination and in transport
databases the vehicle/vessel flows are described from origin to destination. Databases
containing both definitions are very rare. Some sources of this type exist for a limited
geographical area like for instance the trade data of the UK and France.
Using the demand­oriented philosophy we can estimate the future transport flows by estimating
the future trade flows between regions/countries. An important requirement is that the economic
trade relation of the commodity is maintained in the database describing the current transport
flows. Since transport from the producing region/country to the consuming region/country often
takes place with several modes it also has large advantages to have these possible mode changes
in the database. Furthermore if a change of modes (or vehicles) occurs it is also interesting to
have this place of transhipment described. A record structure that includes all these variables
can be called a ‘transport chain structure’; the good is followed from the place of production via
transhipment locations to the place of consumption where several modes can be used.
This transport chain concept has the following characteristics:
1. It is an element of response to the complex situation of transport
2. It has been proven in the past to be a practicable concept
3. It reconciles transport/economical approach
4. It opens ways for more insights in the transport organisation
5. It eliminates double counting
6. It is compatible with current statistics
Databases that do exist with transport chain information are mostly constructed from several
sources where on some places estimates have to be made and inconsistencies can exist between
databases of different countries. Also the level of detail of the transport chain is limited in
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