Salt Lake City International Airport, with two aging terminals and hemmed in geographically, has little room for expansion. However, as Utah's biggest airport, it is developing additional sources of revenue to lessen its dependency on the financially shaky airlines serving Salt Lake without endangering its own fiscal health, according to The Salt Lake Tribune.

Between 2001 and last year, the airline industry lost $35 billion. Only this year, with their airplanes full and their operations more efficient, are the airlines poised to be profitable again.

At Salt Lake, Landing fees and other airline revenues collected by the airport fell to about 25 percent of total revenue last year from almost 30 percent five years earlier. At the same time, revenue from passenger fees and federal grants is soaring. Income from parking, car rentals, restaurants, gift shops and other concessions is also climbing, The Salt Lake Tribune reports.

The upside for travelers and those who do business at the airport is that new shopping opportunities and amenities have been added in the past five years. The downside is that the cost of other key services - from surcharges on tickets to higher fees for rental cars - are hitting consumers in their pockets at every turn.

In 2006, revenue collected from car rental fees amounted to $14.6 million compared to $11 million in 2001, according to the Salt Lake City Department of Airports Revenue Analysis.