An archaic federal law applying to airports in Texas, combined with the merger of Southwest Airlines and AirTran Airways, means the two airlines' passengers won’t be able to fly from Atlanta to Dallas come November. The reduced competition could drive up air fares on the route.

The broken link will remain until Southwest starts serving Atlanta next February and even then, passengers will have to stop in Austin or Houston on flights between Atlanta and Dallas. It's all part of restrictions related to Dallas' Love Field, the city's secondary airport, and Dallas-based Southwest.

The Wright Amendment has been a decades-long issue in Texas, but it never really affected travel in Atlanta until Southwest's acquisition of AirTran Airways this year.

Meanwhile, Delta and American still each have more flights from Atlanta to Dallas than AirTran's seven daily round trips; Delta has 12 daily round trips on the route, while American has 10.

But BestFares.com founder Tom Parsons said the coming loss of nonstop competition from a low-cost carrier like AirTran translates into fares that are as much as $70 higher for Atlanta-Dallas flights.

Southwest-AirTran had to discontinue AirTran's flights to Dallas/Fort Worth International Airport because the Wright Amendment restricts Southwest's ability to fly out of DFW while running its full operation out of Love Field. With the close of Southwest's acquisition of AirTran in May, AirTran became a Southwest subsidiary.

The Wright Amendment, passed in 1979, restricted operations out of Love Field to protect the newer Dallas/Fort Worth airport and the carriers flying into it, including American Airlines. It allows direct service from Love Field only to several nearby states.

But Southwest in 2004 sought to repeal the amendment and regain the right to fly from Love Field without restrictions, using the slogan "Wright is Wrong." Congress passed the Wright Amendment Reform Act of 2006, setting 2014 for the repeal of the law. Until then, nonstop flights on Southwest between Atlanta and Dallas are still a no-go.