In this paper we survey some cases of earmarked taxation. We focus, in particular, on road pricing (that can be interpreted as a tax on traffic flows), and on tourism tax. We show that, in both cases, a pigouvian tax (i.e. a tax used to correct external effects caused by traffic or tourists) can be interpreted as a earmarked tax by simply using its revenue to fund public infrastructures aimed at easing congestion caused by traffic or tourists. We also consider the difficulties of implementing such schemes by analysing a few actual experiences in other countries.