If there's any doubt that competition makes a difference in airfares, take a look at Savannah a year after AirTran pulled its flights. The move left Delta as the dominant airline flying between Atlanta and Savannah, and people in Savannah are unhappy about the fares.

In the third quarter of 2009, Savannah/Hilton Head International was the only airport in the nation to see higher airfares compared with a year earlier, according to the most recent federal report on domestic fares at the nation's top 100 airports. Savannah fares increased 2.5 percent to an average of $396 per round trip at a time when fares at all the other airports declined amid recession and slow travel demand.

Savannah business leaders have complained to Delta Air Lines. "The disparity in fares on Delta traffic into and out of the Savannah/Hilton Head International Airport is having a negative effect, not only on our tourism but also on our local constituents, especially regarding the extremely high fares between Savannah and Atlanta," said the December memo from the Savannah Airport Commission, area chambers of commerce and the Savannah Area Convention & Visitors Bureau.

They said in a follow-up memo last week that a ticket from Savannah to Atlanta costs "in excess of $500" no matter when the traveler buys it. A spot check of Atlanta-Savannah fares on Delta's Web site showed fares ranging from the mid-$200s to more than $500, originating in Atlanta or in Savannah.

"We fully understand that Delta does not want travelers out of Savannah to only travel to Atlanta and that Delta's real desire is for those passengers to contribute to the remainder of your network's hub and spoke system," the group said in last week's memo. But, "we are simply requesting some fairness in the rate structure."

Delta's senior vice president of revenue management, Tom Bach, last month responded that the airline completed a review of its fare levels and found them to be "fully competitive" and "within reasonable tolerance levels." But Delta also acknowledged Savannah's fares were higher than fares out of Jacksonville, and said it adjusted its fares effective Jan. 23 on flights to about 120 destinations.