Two parallel analyses employing contrasting methodologies, using models that were at the leading edge of EU analysis, as well as state-of-the-art techniques and knowledge of industrial and consumer behaviour, were undertaken:

• In the first analysis, the SCENES transport network model has been linked to the E3ME macroeconometric model. This is the first study which combines a full macroeconomic model with a detailed analysis of the transport sector, allowing for changes in both passenger and freight demand and a network analysis of the impact of new infrastructure.
• In the second analysis, the ASTRA model is applied. The model was developed under the 4th research framework programme of the European Commission for strategic assessment of long-term impacts of European transport policy with respect to economic, environmental and social implications. The technical challenge of ASTRA was to demonstrate that the applied system dynamics methodology is appropriate for such long-term policy assessments.

Three common scenarios were defined to provide common model input assumptions for the cluster projects (TIPMAC and IASON). All scenarios are revenue neutral and include alternative options for TEN-T projects funding which are offset by reductions in personal income tax. These policy scenarios were designed as variants in the implementation of the measures the White Paper considers essential to redirect the Common Transport Policy towards meeting the need for sustainable development. These were defined by juxtaposing transport taxation and infrastructure charges as alternative instruments to capture external costs generated by transport vehicles, as well as the main sources to fund a slow or a fast implementation of the Trans-European Transport Network projects in the next decades. More precisely:

• In the first scenario, Social Marginal Cost Pricing is adopted as a key criterion to harmonise infrastructure pricing in the EU together with a slow implementation of the TEN-T core projects.
• In the second and third scenarios, investments flows are anticipated (fast implementation). In the second scenario variant, the bulk of additional funds to fund the fast implementation of TEN-T core projects is made available by means of increasing taxation on fuel, while in the third variant infrastructure charges are levied at social marginal costs.

The impacts of the three scenarios are compared with those of a referenc