Homeless advocates, city officials, police officers and a slew of volunteers converged under the Pontchartrain Expressway near the Central Business District early Thursday morning to clear out the longtime encampment where about 165 homeless people have been sleeping in recent months.

The encampment, which has waxed and waned in size since the 1990s, boomed over the summer, to the frustration of nearby business owners and residents. Critics called it an eyesore and a “no man’s land” where drug use and violence were rampant and a huge rodent population thrived.

Dozens of caseworkers and volunteers, wearing red vests, arrived at 4:30 a.m. They conducted individual assessments of each person they encountered before whisking 84 away to shelters, the city said later.

Charlotte Parent, director of the city’s Health Department, said the homeless were taken to either the nearby New Orleans Mission, the Ozanam Inn on Camp Street or the Salvation Army building on South Claiborne Avenue.

Parent said city officials decided to clean out the area because of deteriorating sanitation conditions. She said the area is infested with rodents, and sanitation crews have been putting down rat traps for months to no avail.

She said the area will be cleaned and barricaded temporarily while the city decides on a permanent solution for keeping it free of homeless people. The space, which is owned by the state, has been cleared in the past, often around large events, but the homeless returned.

In November 2012, two months before hosting the Super Bowl, the city removed 55 people from the area, according to media reports at the time. Ryan Berni, a spokesman for the mayor, said a fence would be built by the end of the year, but it never was erected.

Notices of the latest sweep, which declared the area a “public health hazard” and informed the homeless they had 72 hours to leave, were posted Monday.

Shelter capacities were expanded, and those living under the expressway were told they could bring two suitcases each with them to the shelters.

Parent said the city was doing “everything reasonably possible” to accommodate the possessions of the homeless, but she warned that many of their belongings might be contaminated from the time they spent under the expressway.

“It’s a delicate balancing act,” she said.

The sweep appeared to go peacefully. Although police officers were standing by, there was no sign that any had to be deployed to roust any of the homeless.

Some of the homeless said they were happy to leave the area and go to shelters, while others spoke of plans to migrate to tent cities in other parts of town.

Still, not everyone was happy.

Scott, a 41-year-old man who said he’s been living in a tent under the expressway since February, said he felt he was being stripped not only of his home but also of his sense of community.

“I’m losing my family,” he said.

Homeless advocates have long been in favor of cleaning out the area, saying many of those who settle there would otherwise go to shelters where they could get the long-term help they need.

David Bottner, executive director of the New Orleans Mission, said the city had informed his organization and others about the planned cleanup 10 days ago.

He endorsed the sweep and said the Mission took in 32 people Thursday morning who had been living under the expressway.

“I felt it went very well,” he said.

Bottner emphasized that his shelter and other homeless facilities received no additional funds for taking in extra people and that the organizations rely primarily upon donations.

Sister Alison McCrary, an attorney working for the city’s independent police monitor, was sharply critical of the sweep, which she called an effort to “sanitize” the area in advance of the Saints’ first home game this weekend.

McCrary, who was on the site, said the operation was unconstitutional and violated provisions of both the Fourth and 14th amendments.

“The homeless have property rights, too,” she said.

She said the 72-hour notice was inadequate, especially considering that many of those living under the expressway suffer from substance abuse or mental illness.

“Just think about how long it takes for someone to evacuate for a hurricane,” she said.

McCrary said she worried that important possessions like medication and identification cards could be lost or misplaced while the homeless were transported to shelters.

That sentiment was echoed by Bill Quigley, a Loyola University law professor, who sent a letter to City Attorney Sharonda Williams on Wednesday night asking her not to unlawfully dispose of any property belonging to the homeless.

In his letter, Quigley cited a federal court case in Fresno, California, which limited the rights of that city to take property, such as tents and furniture, from the homeless.

“I ask that you direct the employees of the city not to destroy any property of homeless people but rather to safeguard the property and, if necessary, impound all property of the homeless so that people have a constitutionally adequate opportunity to be heard and to recover their property,” Quigley wrote.

It was not immediately clear how much property the city removed from the former homeless camp.

While some neighbors and business owners said they were happy the city finally shut down the camp, they expressed fear that, without a long-term plan, the area could soon be populated by the transient community once again.

“It should be fenced off,” said Cassandra Sharpe, a real estate agent and longtime critic of the encampment. “They need to not let it happen again. It’s been horrible for our downtown. Anybody who comes to visit sees it. How can you allow that?”

Sharpe said that even though she’s pleased the city cleaned out the encampment, she was dismayed to hear that a new tent city had popped up blocks away at Calliope and Camp streets.

Jeff Keiser, who lives in that block, said he noticed tents moving down toward his home as soon as the sweep was announced.

He said a homeless man was defecating on his block Thursday afternoon and another man was sleeping in the middle of the sidewalk.

“There is little doubt that this migration will get considerably worse in the next days and week,” Keiser wrote in an email. “An update at lunchtime on Thursday indicates that my fears were well grounded as dozens of homeless have arrived and staked their claim.”