Passenger traffic remained on a roll last month, as the county-owned Medford airport saw its second-busiest November.

MEDFORD — Passenger traffic remained on a roll last month, as the county-owned Medford airport saw its second-busiest November.

Boosted by an 18.4 percent increase in Delta Connection traffic, the airport counted 51,101 passengers, a 5.5 percent gain over November 2009.

Through 11 months, 587,022 travelers passed through its gates, essentially securing the airport's second-best year on record.

The annual record of 647,471 was set in 2007. The next two years trended down to 604,690 and 594,532, but flying picked up midway through 2009 and the airport has now seen 18 straight months of year-over-year gains.

"We've just kind of built back up slowly and fares have been reasonable," said Airport Director Bern Case. "That's been the combination for really the whole year."

Case projected the final 2010 passenger figure to eclipse 635,000. During the 18-month rise, he said, July and September produced record months.

While Delta Connection continued a string of good months in November, Allegiant Air and United Express experienced year-over-year gains as well, at 12.2 percent and 8.4 percent, respectively. Horizon Air, which cut one of its Los Angeles flights earlier this year, dropped 0.2 percent — reflecting its relative strength in the market during a month in which its systemwide passenger count dropped 2 percent.

The four carriers combined offer 19 daily departures.

Looking ahead to 2011, Case built a budget based on similar numbers, without growth.

"I'm going with a flat projection because I never like to get stung by over-budgeting," Case said. "I don't really think it's going to be flat, but I don't want to have negative surprises."

Greg Stiles is a reporter for the Mail Tribune. Reach him at 541-776-4463 or e-mail business@mailtribune.com.