During the planning, construction, operation and maintenance of roads, economics plays an important role with pollution mitigation measures providing constraints that have a significant influence on the final cost of the road and its operation. Water protection measurements can represent an important proportion of the total road cost. For example, in Slovenia (a country in which groundwater is a very valuable resource) it was estimated that, over the groundwater sensitive areas, the protection costs represent between 10 and 50% of the total road construction costs.
Roads are constructed due to socio-economic demands and local communication needs. They are among the most important infrastructure objects provided by society’s development. Therefore, it often happens that environmental criteria for their construction and operation take second place to the construction criteria, especially in transition economies. During planning and construction, costs for environmental protection measures are very often treated as direct expenses that cause an unjustified rise in the price of the road. Consequently, it can happen that removing these measures is seen to be a source of savings in the project. Damage to the water environment caused by road construction and operation can be very difficult to evaluate in terms of cost and revenues. However, experience shows that indirect costs caused by incorrect (or omitted) protection measures, although difficult to measure, are very high with long term consequences that can be very difficult to remediate. Roads across drinking water ‘safe-guard’ zones are a particular example illustrating the high costs or high impact that may occur.
A very important economic dimension of protection measures is their operational cost. These costs can represent a large proportion of the total cost of the ongoing road maintenance. Protection measures have to be properly maintained — especially active ones where the run-off is treated before being released to the wider environment. The high operational cost of some run-off treatment systems can lead to incorrect or incomplete maintenance and, consequently, in the generation of a new pollution point at the treatment outlet. Therefore, run-off treatment systems should be carefully designed and costed for all the potential problems that could occur during the maintenance processes.
