Travelers at major U.S. airports are facing security wait times stretching past two hours as the partial Department of Homeland Security shutdown drags on.

Houston George Bush Intercontinental and Atlanta Hartsfield-Jackson have been hit hardest, with some checkpoints closed entirely due to short staffing. Philadelphia International shut down three security lanes after TSA officers called out in growing numbers.

An estimated 2.8 million passengers are flying daily through March and April, a record pace that collides with a workforce stretched thin by the funding standoff. Congressional Democrats have declined to fund the agency, leaving screeners working without pay for the second consecutive pay period.

TSA officials have urged travelers to arrive at least three hours before domestic flights at the busiest hubs. Airlines including Delta and American have extended rebooking windows for passengers who miss flights due to security delays.

The timing is especially painful. Spring break season is pushing airports to peak volumes just as the screening workforce contracts. Travelers with TSA PreCheck or Clear memberships are seeing shorter lines, but standard lanes remain backed up well beyond normal wait times.