A little OT...

Taxi fares will increase 10.5% in January 2016.

Common yellow taxis charge more during the entire month of December.

All other months they charge (bandeira 2) from 21:00 to 06:00, and Sundays/holidays. (When the driver turns on the meter a number 2 will show instead of the normal 1, this costs about 25% more).

Uber is not yet available FROM the airport but a good option when returning to GIG. I paid 69 reais for Uber Black with a 1.3X surge price. (The base fare was 53 reais). It was a typical 44 minute trip from Copacabana-GIG. A new clean Nissan Sentra with great air conditioning. (No yellow taxi lottery).

Disclaimer: I have no financial interest in Uber other than being a satisfied client.