GUÁNICA, P.R. — It was the third interminable night living on the edge of a road in their wrecked Puerto Rico town, but this time the three boys huddled on an inflatable mattress had a welcome diversion: a flat-screen TV perched on milk crates that allowed them to play Mortal Kombat 11.
Hooked up to a portable generator on the bed of a pickup truck, which was parked on a grassy patch off a highway exit, the TV screen lit up as cars whizzed by just a few feet away.
“The night has arrived,” Ana Ayala, 37, the mother of two of the boys, lamented as she put on a sweater to fend off the evening chill. “This is the longest part.”
But many families like Ms. Ayala’s, afraid to go home to buildings that could collapse in future quakes, have insisted on setting up camp in other public spaces — posing a new challenge for strained government services and aid workers. Streets lined with homes look like ghost towns, while parking lots and swales are packed with tailgate chairs, tents and cots.
On Thursday, Rafael Rodríguez Mercado, the Puerto Rico health secretary, urged the evacuees roughing it on their own to move to the government-run camps for their safety — and to avoid an outbreak of gastrointestinal disease.
Encampments like the one on the side of a highway in Guánica have no access to running water or bathrooms.
It is not that Ms. Ayala and the five other families camped there — all relatives, friends or neighbors — do not want the assistance provided at a government-run shelter.
But José Luis Casiano, Ms. Ayala’s husband, wanted to be on higher ground and closer to the highway leading out of town in the event of a tsunami, perhaps the biggest fear among residents following more than a week of unsettling tremors. Mr. Casiano and the others first ventured to the grassy patch on Dec. 28, though at first they spent the night in their cars.
After Tuesday’s big shake, which briefly triggered a tsunami watch and set local sirens blaring, the families deployed in earnest, parking a half-dozen S.U.V.s in a protective semicircle around their blue tent.
“I haven’t seen a bed since Three Kings Day,” said José David Quiñones Nazario, 40, as he sat on a patio chair, mosquito zapper in hand as the insects swarmed at dusk.
Two chairs down, Fenixa Muñoz quietly rocked her sleeping 6-month-old son, Matthew. His playpen was a few feet away. The quake leveled the bakery Ms. Muñoz and her husband, Germaine Vélez, 34, opened nearly three years ago. Fourteen employees were left jobless. Their 10-year-old son, Sebastián, has not wanted to eat or sleep or speak much since the temblor.
The bakery’s big generator is now set up in the camp, used at night to turn on one of three spotlights.
“Guánica is destroyed,” lamented Mayra Rivera, 38, Mr. Quiñones’s wife.
The quake knocked over everything inside her house, she said. She has to sign up for a structural engineering inspection but has not done so yet. It is all too overwhelming.
“I’ve been showering in the patio of my house,” said Gladys Rodríguez, 68, Ms. Rivera’s mother. “I won’t go inside.”
Ms. Ayala’s 10-year-old son, Yonatan Elí García, wearing red swimming trunks, improvised a shower on Wednesday afternoon by standing behind an open S.U.V. door while his grandmother held a modesty towel on the other side and his grandfather poured a gallon of water over his head. The evening coffee came out of a Mr. Coffee pot balanced on a crate and plugged into the portable generator.
A towel and jeans air-dried on tree branches. Between two sets of trees, Mr. Casiano, 37, strung a pair of striped hammocks. From the tent hung a stalk of green bananas.
Complicating the return home, about half of the island — 850,000 customers — remained without power on Thursday. José Ortiz, the director of the Puerto Rico Electric Power Authority, said the public utility hoped to fully restore electricity by Sunday, but his rosier estimates earlier in the week have proved wrong. Gov. Wanda Vázquez was more cautious.
“We can’t speak of exact dates,” she said. “No one can say that.”
Transportation officials closed a portion of the main highway from San Juan, the capital, to the damaged southern town of Ponce, citing serious structural damage to the roof of a tolling plaza near Ponce.
Federal Emergency Management Agency officials sat down with local mayors on Thursday to assess their needs. One mayor, Ángel Luis Torres of Yauco, said he walked out of the meeting in Ponce frustrated by the onerous bureaucracy in his attempts to get water, generators and tents to the nearly 3,000 people in his town who are sleeping outside.
He fears that people will refuse to return home until engineers inspect their homes. But with some 300 houses damaged by the quake in his town alone, inspectors are scarce.
“How are we going to tell people to go back home?” Mr. Torres asked.
At the roadside camp in Guánica, municipal workers have come by every day to fill a huge potable water container, which Ms. Ayala and her friends and neighbors use to rinse silverware and wash up.
On Wednesday night, the Rev. Luis Vidal Ortiz from the Iglesia de Dios Pentecostal pulled up in a small yellow school bus and delivered packs of chips, cookies and personal hygiene products. He invited the families to visit the church for a hot meal on Friday. Later, a convoy of flatbed trucks, led by the mayor and other public officials, came by with water bottles. A crew installed a portable floodlight across the street for safety.
At the nearby sports complex where the government is running a local camp, evacuees had access to indoor bathrooms — albeit without running water — as well as to a mobile clinic, a dinner of arroz con pollo, volunteer physicians and a group of psychologists offering art therapy and crisis counseling.
The families at the roadside encampment acknowledged that they felt, indeed, in the middle of a crisis. Mr. Casiano’s eyes welled with tears remembering the big quake on Tuesday. His German shepherd, Zukari, had been acting strangely right before, breathing hard and raising her head in alert, he said. Since then, “we’ve felt the earth shake even when it’s not shaking,” Mr. Casiano said. “At night, we shiver twice: from the shaking and from the cold.”
“We’re staying until the power comes back on, and the water,” he added. “Or if the police evacuate the town.”
Moments later, Zukari, who was leashed to a tree, barked. The ground quivered.
Ms. Ayala called out a warning of a new aftershock: “¡Tembló!”
Alejandra Rosa contributed reporting from Ponce, P.R.