trends and future of sustainable development - TransEco

Figure 1.The framework for analyzing the CO 2 intensity of road freight operations.The framework disaggregates the relationship between the economy and CO 2 emissions into keyratios which can be analysed to find out the causes for changes. However, by doing that some complexitymay be lost and one should be cautious not to lose sight of the various feedback loops between the keyratios. While the framework includes the modal split, other modes of transport are omitted from theframework, but similar analysis can be made to other modes and changes in key ratios in other modescan affect road freight. The geographical scope of the study is also an important issue, as highlighted inthe earlier discussion about off-shoring. It can be seen from the various studies cited by Lehtonen(2008) that analyses have mostly been made on national level as the data is best available for that scope.As van de Riet et al. (2008) point out there is limited and scattered data available for freight analysisbecause of a variety of units for measuring freight movements, confidentiality issues, various decisionmakers involved in a shipment and different types of loads. The solution they propose is to combine bothquantitative and qualitative data from several sources.The framework has mainly been utilised for studying the changes that have affected the road freighttransport sector. It has also been used somewhat, and increasingly, for forecasting the futuredevelopment of road freight transport and its environmental effects, mainly CO 2 emissions. Piecyk(2010) forecasts the CO 2 emissions of road freight transport in the UK by combining focus groupdiscussions, Delphi survey, scenarios and spreadsheet modelling with the framework. This variety ofmethods was chosen since the accuracy of forecasts which rely on trend extrapolation or linking freighttransport with economic development was considered low. This was because extrapolation and linkage439