More than 16 million passengers are expected to fly on U.S. carriers during the long Labor Day weekend, including several thousand in and out of Missoula.

With a new passenger terminal under construction and the old facility packed full, local airport officials are planning now for what's expected to be a challenging weekend.

“We do expect Labor Day to be busy,” said Cris Jensen, director of Missoula International Airport. “It's the last chance for people to get trips in before school starts. Labor day tends to get a little busier than the rest of the summer.”

Airport officials this week began looking at parking and how to address an influx of holiday travelers. Jensen said they'll bring on extra staff to ensure passengers reach their gate despite the crowd.

“We're all aware this is coming, and I think we're in a good place staff wise,” Jensen said. “The terminal is being pushed to its limit, and this year, I'm relieved that it's mostly over and we survived it.”

After years of planning, the airport this summer broke ground on a new passenger terminal, one needed to handle the year-over-year increase in passengers.

The airport is up more than 12 percent in passengers this year over last year. It has border more than 452,000 passengers over the past 12 months. In comparison, it finished last year at 424,000 passengers.

Jensen said the challenges are likely to remain until the new facility opens in the fall of 2021.

“We were aware of what was coming with construction and we've made preparations for it, but it didn't go as smoothly as we would have liked this summer,” Jensen said. “We'll have an end-of-summer debriefing, where we'll sit down with all our stakeholders and talk through how it went and what we can do better next year, knowing we'll still be in the middle of all this construction.”

According to the Airlines for America trade group, an estimated 16.5 million passengers will fly worldwide on U.S. carriers over the Labor Day weekend. Friday is expected to be the busiest, when nearly 3 million passengers board a U.S. airline.

After the Labor Day weekend, a number of seasonal flights serving Missoula will end for the year. That will give passengers more room in the dated terminal and airport officials time to plan for the next two summers, when the process starts over again.

“I actually think the summer of 2021 we won't have moved into the new terminal yet,” Jensen said. “It'll be close. But it's looking like fall 2021. As we continue to grow and see more airplanes, more seats and more people, it's going to get more challenging as we get closer to that date.”