Two airlines have announced they are extending service at Raleigh-Durham International Airport in the coming months.
Frontier Airlines is upgrading its RDU to Trenton service to year-round. Separately, Southwest Airlines is expanding its existing service from RDU to Phoenix to year-round.
Both carriers had offered the flights on 10-month cycles, opting out during January and February, says airport spokesman Andrew Sawyer.
The two carriers are the only airlines offering those routes out of RDU....