If optimum resources are allocated, there is not a great deal
of difference between the total current benefits achieved with
the different financing mechanisms applied in this research.
For this reason, if the State is suffering from serious budgetary
constraints, a higher economic optimum will be achieved
if the financing mechanism implemented is directly linked to
traffic volume, such as an earmarked fuel tax or a set charge.
To sum-up, the most important issue for achieving the highest
economic efficiency is not the financing instrument used
but a guarantee of having the necessary resources available
to cover the optimum maintenance expenses