The guidelines for the development of the Trans-European Transport Network (TEN-T) require the development of methods for strategic environmental assessment (SEA) of the network and individual corridors (Decision 1692/96/EC). This is to ensure that the full environmental impacts of the policy initiative are assessed, and not just the impacts of individual sections of infrastructure. In response, the Commission co-ordinated a number of research actions to perform a pilot SEA of the TEN-T.
COMMUTE had three main objectives, to:
- define a methodology for strategic assessment of the environmental impacts of transport policy options;
- develop software embodying the main quantitative elements of the methodology;
- test the methodology and software in the context of a pilot SEA of the plans for the TEN-T.
COMMUTE delivered two main end products:
- a methodology for SEA of transport policies, plans and programmes;
- a software tool for assessment of air pollutant emissions, energy consumption, noise and safety impacts.
The SEA methodology comprises:
- a framework covering the basic methodological requirements for SEA of multi-modal transport developments, together with guidelines on the integration of various analytical approaches (such as cost-benefit and multi-criteria analysis);
- detailed methods for assessing major types of impact (emissions, energy, noise, safety) for road, rail, air and waterborne transport. Methods for other impact categories such as land use and ecological damage are also outlined.
The software tool embodies the detailed methods. It focuses on impacts at European, national, regional and corridor levels, aggregated from the impacts associated with individual transport links and nodes (such as urban areas, harbours and airports). The calculation includes the life-cycle emissions for power stations and refineries. Output data are presented in a Geographical Information System, and also are differentiated according to the height of emission into the atmosphere. External input data include traffic flows and vehicle fleet composition.
A pilot SEA of the TEN-T was conducted in collaboration with three other projects. Each link and node in the TEN-T was assessed. The interfacing of the COMMUTE software with a transport model was also demonstrated, and comparisons made between COMMUTE results and those from other models.
The pilot SEA work provided an initial quantification of the impacts of TEN-T policies and infrastructure, and also demonstrated the feasibility of the SEA methods. TEN-T is projected to increase overall passenger and freight travel demand, but with a substantial shift to rail and a reduction in road network congestion. Road vehicle emissions (other than CO2) will fall, while the air sector will see substantial increases in total emissions. TEN-T is estimated to reduce CO2 emissions relative to a do-nothing scenario, and to improve traffic safety.