Samenvatting
In this paper the problem whether to invest additionally for measures that meet environmental effects is approached by means of a cost benefit scheme. Increasing wealth creates room for increasing extra investments. It is also required by the population to meet better environmental quality standards. The value of environmental effects can be determined from the money one is willing to spend on the related measures. A financial allocation mechanism should be based upon a separate budget for environmental measures, to be spent on transport efficient projects and on measures with a high return. (A)