And if one considers only the land, should this be priced at the same level as the neighbouring land,
which would probably be different if the infrastructure did not exist? It is interesting to examine the area of
the different systems, but one must be careful not to draw too rapid conclusions and to avoid measuring the
same data twice.
Subject to these reservations, the following are the figures given by the Commission of the
European Communities Green Book (1992) on the impact of transport on the environment: