The head of the TSA told Congress Wednesday that his agency is understaffed amid concerns growing over long lines at the airport and days before one of the busiest travel weekends of the year. Washington bureau reporter Alberto Pimienta filed the following report.

If you cringe at the thought of long airport security lines, brace yourself.

"I do think that we are at a lower staffing level than we need to be to meet peak demands at peak periods. And we're working the staffing models now, aggressively, with the airlines to determine the right number," said TSA Administrator Peter Neffenger.

In many airports, travelers have seen wait times double. Hundreds of passengers at airports like Chicago O’Hare have missed their flights waiting to go through security.

Lawmakers say in 2011, there were 45,000 TSA screeners for 642 million passengers. In 2016, there are 3,000 fewer screeners for roughly 740 million passengers.

During the hearing about long TSA lines, Neffenger says an extra 768 screeners will be in place by June 15.

Amid the backlash, the TSA revealed a new system at the Atlanta airport, one of the world’s busiest. The new screening process now sends suspicious bags to a separate belt to keep the lines moving, and there are now new areas where passengers can take their off shoes at their own pace.

But just days away from a record-breaking summer for air travel, a possible warning:

"We have a challenge this summer, which we are aggressively meeting head-on," Neffenger said.

Until they do, the lines may be here to stay.