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

D5 Annex WP 3: DATABASE METHODOLOGY AND DATABASE USER
MANUAL – FREIGHT TRANSPORT DEMAND
4 THE FREIGHT OD DATA MODEL
4.1 Introduction
In this chapter the proposed freight OD transport chain data model is described. The exact
structure of the type of model to be used is depending on the specific structure of the available
data. For this reason not all details but merely the basic principles and available tools will be
discussed. The exact model in full detail will be developed along the construction process in the
remaining of the project. Some results obtained in the testing phase are already described in
chapter 6.
4.2 General structure
The general structure of this model to be used can be split up into the following parts:
1. Combining trade/transport/transhipment data sources
2. Estimating data gaps
3. Adding information to the OD matrix
In the first part all available trade and transport data sources are being combined into one
database by a top­down approach. This approach will have the same structure as the NEAC
database construction model. It might be the case that some regional information is missing in
transport or trade data or that no data are available at all for a specific geographical area. In this
case estimation methods are required that can estimate data by modelling. Next procedures will
be applied to add information to the OD matrix. Container information, cargo type information
and characteristics on the OD flows will be estimated. Also estimation procedures will be
applied for the translation from tonnes to vehicles/vessels and if possible by type, translating
containerised tonnes into TEUs. Finally all this information will be used to determine transport
performance information (tonnekm, vehiclekm/vesselkm and TEUkm). This will be described
in more detail in the following sections.
4.3 Combining trade/transport/transhipment data sources
The first step in the top­down approach is to combine all collected trade/transport sources into
one database. Here we use the trade data as the foundation of the whole database and refine this
with information that can be found in the transport and transhipment data sources. In the
INFOSTAT project a pilot database has been constructed with the top­down approach. As
described in paragraph 6.4 there are some restrictions on data combinations. In INFOSTAT a
database with two transhipment points has been constructed. A conclusion was that for all
elements of the chain, data should be available to ensure quality of the results.
Up to this point two transhipment points in the chain structure by combining sources seems to
be the limit on the level of detail.
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27 May 2004
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