NeTEx can be used to describe zone based fare systems of any topology ranging from a simple  patchwork (adjacent zones) to the complex, (honeycomb, doughnut) etc). The TARIFF ZONE allows zones to be associated with stops and stations. Mixed zonal and stage systems are also possible. Fare pricing may be a flat fare system per zone, or   zone to zone using a (DISTANCE MATRIX ELEMENT), or be differentially priced for particular sequences of zones (using FARE STRUCTURE ELEMENTs in SEQUENCE)