The municipal government sets or authorizes the Zona Azul rate. An operator may submit studies or requests allowed by the contract, but it cannot change the public price on its own.
The rate may be established in a local law, decree or concession agreement. Those documents can also define period length, vehicle categories, areas, exemptions and the adjustment formula.
Adjustment and review are different
- Adjustment: a periodic update under an index or formula already written into the agreement.
- Review: an exceptional reassessment when documented events materially alter the contract's economic balance.
Both require a legal basis and a valid administrative act. A statement that costs increased does not by itself change what drivers must pay.
To verify an increase, find the latest tariff act, its effective date, the tender and contract, and any amendments. Compare them with official information and street signs. The app applies the registered rate; it is not the legal source of the change.