Ticketing
The Amsterdam public transport network falls under the National Tariff System of the Netherlands and the GVB has a few of its own tickets, notably the 24-, 48- and 72- hour tickets. The electronic OV-chipkaart has been the only ticketing system valid in the Amsterdam metro since the summer of 2009, and in the rest of the network (tram, bus) since June 2010. Most trams carry conductors, but as they no longer stamp passengers' strippenkaarten their role has been deskilled; it now consists in ensuring security along with selling the occasional OV-chipkaart and optionally announcing the stops.
Read more about this topic: Gemeentelijk Vervoerbedrijf