Those long security lines at Denver International Airport are “rough and getting worse.”

With the holiday rush nearly here, and a record number of annual passengers expected at DIA this year, some members of Colorado’s congressional delegation are calling on the Transportation Security Administration to step in.

DIA has experienced an “unprecedented increase” in the number of passengers it serves but the number of TSA personnel and resources assigned to DIA have been decreasing, according to a letter penned by multiple members of the Colorado congressional delegation and sent to TSA Administrator David Pekoske on Monday.

The letter also pressed the TSA to provide more transparency around how the agency decides what level of resources to provide airports, a request echoed by DIA.

The TSA initially declined an interview request. A spokesperson later provided a statement saying the agency coordinates closely with airports and air carriers to prepare for projected increases in travel volumes. The TSA staffs security lanes based on projected passenger volumes, the statement said.

“We do our best to maintain our wait time standards of 30 minutes and under for standard screening lanes and 10 minutes and under for TSA PreCheck screening lanes. TSA’s standards are to wait times, not the length of the line,” the statement said.

TSA screened a record number of passengers at airports across the country this year, the statement said.

The TSA also outlined travel tips to help with navigating security. Those tips included arriving to the airport at least two hours early, using the TSA’s “What Can I Bring?” tool when packing, assisting children with packing to ensure they do not include prohibited items, knowing the TSA’s liquids rules, and having identification ready for agents, among other suggestions.

The letter from lawmakers was signed by U.S. Sen. Michael Bennet, U.S. Sen. John Hickenlooper, U.S. Rep. Ken Buck, U.S. Rep. Brittany Pettersen, U.S. Rep. Joe Neguse, U.S. Rep. Diana DeGette, U.S. Rep. Jason Crow and U.S. Rep. Yadira Caraveo.

DIA has become the nation’s third busiest airport. Some 69 million people passed through the hub last year, which is on track to see 78 million passengers this year. That is five million more than what DIA initially anticipated, the delegation members wrote, and would be a record.

On X, formerly known as Twitter, Crow said he signed on to the letter because wait times at DIA are “rough and getting worse.” Bennet called the airport “a vital fixture for travelers across the country” but also one left “understaffed and strained for resources” amid the influx of passengers.

June alone saw 6.7 million passengers come through DIA, according to the letter. The lawmakers’ letter added that the TSA has allocated fewer roles for DIA today than it did in 2019 despite passenger volume climbing by the millions.

“We write to request that the Transportation Security Administration (TSA) take all appropriate steps to fully deploy resources at Denver International Airport (DEN) in response to the unprecedented increase in travelers the airport has experienced this past year,” the letter said.

DIA’s growth is not expected to slow down. The airport forecasts it will hit 100 million annual passengers in less than a decade and 120 million passengers by 2045.

Stacey Stegman, DIA’s senior vice president of communications, marketing and customer experience, said DIA has a good working relationship with its local TSA branch but that it, too, wants more clarity about TSA decision making.

“More our questions have been about, how is it that our passenger traffic continues to increase and yet our TSA resources are decreasing,” Stegman said.

As DIA has grown busier, its security lines have begun experiencing traffic flows similar to a highway system’s rush hour, she said.

“The vast majority of the time, wait times are within a normal standard that you would see at any airport,” she said. “There are those other times though when there are large banks of flights, and that is when the wait times far exceed acceptable levels.”

In the busy mornings and afternoons, lines can exceed an hour’s wait, stretch past the baggage claim and wrap around the terminal.

“We’re seeing it happen several days a week now, and sometimes multiple times a day,” Stegman said.

DIA employees help direct people waiting in line, but it is the TSA that determines how many lanes are open at security checkpoints and how many of its personnel are working.

“This is certainly not a criticism of them, but we are trying to understand more to see what can be done to improve the lines and the experience,” she said.

This story has been updated with a statement from the TSA.