The Venezuelan authorities have restricted access to the country’s worst-hit disaster zone, as an outpouring of support after Venezuela’s devastating earthquakes has become, in places, an obstacle to the rescue effort.

As trucks and motorcycles rushed toward the battered coastal state of La Guaira in recent days carrying food, water and medicine, traffic choked the only highway into the disaster area, delaying ambulances and rescue crews. On Saturday morning, the authorities restricted access to government vehicles and other authorized personnel only, saying the flow of civilian volunteers had become unmanageable.

A widely shared video on social media showed an aid worker pleading with volunteers to stop driving into La Guaira, warning that traffic had prevented rescue crews from reaching survivors who remained trapped beneath collapsed buildings.

“There are people still alive,” she said. “We have the rescue team here, but there are too many people bringing supplies.”

She added that a damaged bridge had shifted several centimeters under the weight of traffic and risked becoming impassable.

The aid worker urged people to leave donations at collection centers in Caracas instead of transporting them to La Guaira themselves.

“I need you to let us do our work,” she said. “We have the doctors, we have the supplies, but they can’t get through.”

On Friday, the road from Caracas to La Guaira was packed with buses, cars, aid trucks and motorcycles carrying water, shovels and ropes, among other supplies. The trip, which normally takes about an hour, stretched to roughly four hours. Some medical workers abandoned their vehicles and continued on foot in the heat, while Red Cross trucks sat immobilized by traffic.

The congestion has compounded the logistical challenges facing rescue workers, according to Josué Araque, a disaster-risk expert at the University of the Andes in Venezuela.

Damaged roads and a weakened bridge into La Guaira had already slowed access, while the constant flow of motorcycles and private vehicles created noise that could distract rescuers listening for survivors trapped beneath rubble, he said.

Many Venezuelans prefer to deliver aid directly rather than through official channels because they distrust government institutions, he added, contributing to the bottleneck and prompting the authorities to “make difficult, unpopular decisions” like restricting access to the disaster zone.

“That’s standard practice: You secure the affected area to prevent disease, control the number of people entering and avoid creating even greater problems,” he said.

The authorities set up a permit system for entry, but it has been overwhelmed by applications. Now even families of hospitalized victims have struggled to obtain permits to enter La Guaira, according to Mr. Araque.

Despite the restrictions, traffic remained congested on Saturday morning. A reporter working for The New York Times observed heavy machinery, debris removal trucks and government vans heading toward La Guaira alongside private vehicles. Ambulances wailed through traffic as emergency workers ran ahead, waving vehicles aside. Health workers rode in the backs of pickup trucks. There was a minor collision between a pickup truck and a motorcyclist.

Jesús Pacheco, a 26-year-old electronics student who drove five hours on his motorcycle to transport medical supplies, said the entrance to La Guaira on Friday had became chaotic as vehicles loaded with aid flooded into the disaster zone.

While the solidarity was striking, he said, he began to wonder whether the overwhelming response had become counterproductive.

“We sometimes forget that it’s better if we’re organized,” he said. “In our eagerness to help, we end up making things more difficult. But we do what we can.”