Increasing the sustainability of the transport system is high on the agenda of the European Commission.
Adequate policy measures are needed to finance the infrastructure requirements and to achieve the EU target of at least 60% reduction in greenhouse gas emissions by 2050 with respect to 1990 (EC, 2011a).
Moreover, efficient strategies need to be developed to reduce other external costs of transport such as congestion, noise hindrance and traffic accidents.
Thus, improving transport efficiency and sustainability using the price mechanism is a key objective of research projects
funded by EU.