It seems to me that the TSA screening at the airport is set up so there is always a long line. They open late, so that people have gathered to board early flights, so that there is a long line.
Then they don't open any more lanes until the line is out the door. As soon as the line gets lower, they close or two lanes until the line builds up again.
It's the opposite of Target or WalMart, who open new lanes when a few people are waiting. The goal of TSA is to make sure someone always has a long wait.