For most Americans, Spring Break has come and gone. But lines at many airports, especially at busy hubs, remain.

A lack of funding for the Department of Homeland Security (DHS), which includes the Transportation Security Agency (TSA), is core to the problem. Since mid-February, TSA employees have been left unpaid; hundreds have quit, while hundreds more have called out of shifts.

The situation is especially precarious at airports like Houston’s Hobby (HOU) and Bush (IAH),New Orleans(MSY), Atlanta(ATL), Baltimore(BWI), and New York (JFK), which seen peak callout rates exceed a third of staff. Staff spread thin in these locations have been forced to shut additional lines, resulting in hours-long waits and missed flights.

Houston, we have a problem

If there were an epicenter of the ongoing TSA crisis, it might be Houston, Texas. Both of its international airports have faced steep callout rates and resignations, as well as hour-long waits.

Houston-Intercontinental (IAH) has even been forced to close the majority of its lanes, leaving travelers with just two options when they head to the airport, in Terminals A and E. Waits to exceed three hours have not been uncommon, even during slower periods at the airport.

And TSA PreCheck and CLEAR are no guarantee, either. On Monday and Tuesday, IAH shut down Known Traveler Lanes amid a shortage of staff.

“Airport conditions beyond our control are affecting service at IAH, where only standard screening is available at the moment. We recommend travelers check with their local airport for the latest updates.” Kyle McLaughlin, EVP of Aviation at CLEAR told TheStreet. “Now, more than ever, we want to thank the Transportation Security Officers for their continued dedication to ensuring secure air travel, and we hope a resolution comes soon.”

When will the travel troubles end?

In the meantime, airlines have warned travelers to show up much earlier than usual for their flights, or to consider changing them for free.

The good news is that a resolution (literally) could be coming soon in the House of Representatives. While President Donald Trump urged Congressional Republicans to resist any bill that would leave parts of DHS unfunded, legislators have been angling to pass legislation to end the air travel chaos by funding the TSA, then working through the remaining details.