Model for development of freight transport
In the starting phase of this research project two different sets of data have been constructed (by Statistics Denmark): one of the datasets includes information on the level of transport measured in tonnes and in traffic performance and trips. The second dataset describes developments in production measured in physical terms as well as in values (1980 DKK) segregated on groups of commodities and production sectors.
The aim of the present project is to establish a forecast model which can describe the relation between the economic development and the freight transport, and the related energy consuption and emissions. The model will be implemented as a satellite model for ADAM, and will be used for analyses of the relation between transport, energy consuption, emissions and the development of production and changes in the production structure. The point of departure for the modelling is a combination of the model presently used by the Ministry of Transport for forecasting purposes and the model implemented as a satellite in ADAM. Variables such as the total vehicle miles, energy consumption per mile and emissions are calculated based on technical information, and the model may be used for analyses of changes in, for instance, the load capacity of vehicles, the capacity utilisation rate, energy efficiencies and emissions
Detailed analysis of the two datasets have been carried out in order to explain the observed trends in the data. Simultaneously, a conceptual model describing how the two sets of data can be connected in a model, has been developed. The primary contribution from the project is this conceptual model, which describes the connection between economic activity and physical transport at a level of detail beyond any previously known models. The insight obtained from this is unique and very usable not only in order to understand the relationships, but even more so in the analysis of which elements are the most important when considering the development in road freight transport. The final (and larger part) of the project has been devoted to looking at the dynamics in the model, through estimates of relevant relations from the conceptual model. The hypothesis - that the development can be explained by different price- and cost variables - could not be confirmed. In most cases a technological trend could be supported as an explaining factor. These trends are used insted the underlying structural relationships, which we have not been able to find any good approximations for. Altogether, the individual elements in the model have been described satisfactorily, however, not all with the same degree of (statistical) accuracy. One explanation for this is the (relatively) high aggregation level used in which homogeneity cannot be obtained in the different samples of data. The model has been tested on a prognosis carried out by the Department of Finance in spring 2000. The conclusion based here upon indicate a tendency to overestimates of the development in traffic as a result of the economic development. This conclusion is supported by a socalled backcasting, where the model is used in order to describe the historical development on which the model has been developed. Part of the overestimation can be explained by poor data in some cases, the timeseries were relatively short. We have discussed the different trends an excluded trends that seemed to high. However, this is not equivalent to correct estimates in all cases. Generally, it must be concluded that the trends does seem a bit on the high side. However, we have not found any indication in the data telling us to change the trends
Key figures
Category
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| Danmarks Statistik. | ||
| Transportrådet |
Contact
Postboks 358
DK-4000 Roskilde, Denmark
Møller Andersen, Frits (seniorforsker); Projektleder: Kveiborg, Ole , 46301200, FMA@DMU.DK
Øvr. Partnere: Danmarks Statistik; Transportrådet
