HOUSTON — It’s Holy Week, and on the U.S.-Mexico border that’s an especially busy time for trade, tourism and shopping.

April is also the height of Mexican produce season, and just south of the border in Texas, lines of idling tractor trailers stretched for miles waiting to enter the United States.

This year, the traffic jams at the border crossings are especially bad, because the federal government has reassigned 750 staff members from their usual duties at ports of entry and inland checkpoints to help deal with large numbers of Central American immigrant families who have been showing up at the border to claim asylum.

Through March of this year, a total of 189,584 people traveling in families sought asylum at the southern border — a 374% increase compared with the same period last year.

According to Border Patrol policy, all those migrants must be taken to holding areas to be “processed”interviewed, fed and screened for medical issues.

The agents were reassigned this month after President Trump declared a national emergency. Now communities along the border are starting to feel the consequences.

On Thursday, three Texas congressmen held a briefing at the Laredo port — the country’s second largest by volume after Los Angeles — to call for the return of customs agents.

They said they had been contacting Border Patrol officials for weeks, offered suggestions to alleviate delays, and received assurances the agency would address the problem.

Customs officers staff 328 ports of entry on the southern border. Many of the crossings include multiple booths and several lanes of traffic. Some cater exclusively to commercial traffic.

“They are a catalyst for economic development in the Rio Grande Valley,” said Rep. Filemon Vela, who represents part of the region. “Our communities need immediate relief from the extended wait times at border crossings.”

Rep. Vicente Gonzalez, who also represents the valley, said the Trump administration appeared to be ignoring local feedback.

“It is inexcusable that the concerns, questions and ideas of local officials, business owners and citizens have fallen on deaf ears,” Gonzalez said.

The ports aren’t the only problem. U.S. Customs and Border Protection runs about 170 inland checkpoints, concentrated in the zone 100 miles north of the border.

At the checkpoints, Border Patrol agents with drug- and people-sniffing dogs stop and at times search vehicles, questioning drivers.

The Border Patrol has long stressedthe significance of checkpoints in catching smugglers of people and narcotics and publicizing major busts and programs like Operation Big Rig, created to target tractor-trailer smuggling.

Some El Paso-area checkpoints are notorious for drug seizures, like Sierra Blanca, dubbed “Checkpoint of the Stars” by Texas Monthly for busting tour buses of celebrities including Willie Nelson and Snoop Dogg.

Last month, Border Patrol officials closed checkpoints in southeastern New Mexico and west Texas, and redirected staff to process migrant families. Vehicles that would have been stopped and inspected now flow north freely.

In southern New Mexico’s Otero County, commissioners voted to demand that the governor deploy National Guard troops to reopen the checkpoints and declared a state of emergency Thursday.

“If this demand is not met by the state of New Mexico in one week’s time, the county of Otero will take action itself to provide security and safety and well-being for the people in this county,” said Couy Griffin, who leads the county commission.

Griffin said county officials might also sue the state for “failing to follow its constitutional duties.”

Gov. Michele Lujan Grisham, a Democrat, refused to reopen the checkpoints.

In February, she had pulled remaining National Guard troops, deployed last year by her predecessor, Republican Gov. Susana Martinez.

“If Otero County officials are unhappy that a federal checkpoint has been un-manned, so to speak, their concerns would have the best chance of being addressed if registered with the federal agency that made the decision to shift that personnel elsewhere,” said Tripp Stelnicki, a spokesman for the governor’s office.

Along many parts of the border, checkpoint closures are rare, usually occurring only before storms and other hazardous weather.

In Texas’ Rio Grande Valley — the border’s busiest smuggling corridor — checkpoints close only to allow people to flee during disasters, such as Hurricane Harvey in 2017.

Acting Homeland Security Secretary Kevin McAleenan, a former Border Patrol commissioner who took over last week after Kirstjen Nielsen’s ouster, said this week that processing migrant families remained a crisis.

He did not indicate whether checkpoints would reopen anytime soon.

“It’s clear that all of our resources are being stretched thin,” he said after a visit to Border Patrol migrant holding areas in McAllen, Texas. “The system is full, and we are beyond capacity.”

And so as Easter approaches, cars remain snarled in border traffic, some Mexican shoppers are planning fewer trips north, and workers and students who travel daily between Mexico and the United States worry about arriving on time for their shifts or final exams.