There is a fixed rate schedule posted at the airport adjacent to the taxi dispatcher. All taxi drivers are required to carry and provide a rate sheet upon request of a passenger. There are numerous online sources showing the rates with a simple Google search. Recently the taxi association has added a $10/cab/day fee for drivers not members in the association that is based in the airport that is paid by the cab driver. If you walk out of baggage claim and get in a random cab the driver is in the airport association. If you call a separate cab from a driver that isn't doing a lot of airport trips, the driver may add a few bucks to help offset the fee. As wisely suggested, ask what the total cost will be before you get in. All fares are regulated.