KABUL — Taliban checkpoints have proliferated across key parts of Afghanistan as U.S. forces have withdrawn over the past year, leaving Afghan towns and cities increasingly isolated and impeding the Afghan government’s ability to function.

Dozens of temporary Taliban checkpoints now dot the main highways leading into and out of the Afghan capital, according to eight local officials, and more than 10 permanent outposts have been established by the militants along the country’s main north-south highway. Many of the new permanent outposts are checkpoints abandoned by government forces stretched thin by the U.S. drawdown, pushed out by expanding Taliban influence, or both.

Taliban checkpoints are both a symbolic show of force and a real blow to Afghanistan’s already fragile elected government. The outposts — both temporary and permanent — along major highways frustrate military resupply efforts, stifle the provision of government services and undercut confidence in the country’s elected officials.

The new checkpoints have emerged as Afghanistan enters a pivotal period. NATO troops began drawing down Thursday, according to media reports and an Afghan official who spoke on the condition of anonymity to discuss the matter. U.S. forces are set to reach zero by Sept. 11, a deadline originally scheduled for May 1. The Taliban’s encroachment on critical roadways is one of many signs that the group is undiminished after 20 years of war and appears to be pressing for a military victory as foreign military support for Afghan security forces is cut back.

“It is like we are on an island,” said Mohammad Yousuf Ayoubi, the head of Kunduz’s provincial council, describing the province’s capital city. “I can’t drive more than four kilometers in any direction without hitting a Taliban checkpoint.”

A little over a year ago, Ayoubi would drive himself the nearly eight hours south from Kunduz to Kabul for meetings. Today, that is impossible. Government officials are largely forced to make the journey by air, and if they do travel by road, they do so in armored convoys with heavy security.

The Afghan government has struggled to maintain control of its highways since the beginning of the Taliban resurgence in 2005, but the situation has steadily deteriorated as the number of U.S. troops in the country has dropped.

When U.S. military bases began closing across the country after the signing of the U.S.-Taliban deal, Afghan forces suddenly found themselves stretched thin. With less U.S. support, Afghan police and soldiers could not hold the same amount of territory. They moved inward to protect population centers, leaving large swaths of Afghanistan’s rural territory — and the roadways that crisscross it — largely unguarded.

At the same time, the Taliban doubled down on territory under its control, moved into unsecured areas and actively pushed to expand its areas of influence. With the cessation of offensive U.S. military airstrikes, the Taliban was able to set up permanent checkpoints where highways crossed long-held districts and send out hundreds of fighters to patrol, according to local officials.

Restricting the movement of government officials, Ayoubi said, makes it almost impossible for them to do their jobs. “We used to drive out to the villages to every district and talk to the people,” he said. “Now that we cannot speak to the people, how can we know what their problems are?”

Kunduz has been one of the least stable provinces in Afghanistan for years, and its capital fell to the Taliban in 2015, but it has never been as isolated as it is now, Ayoubi said.

“Day by day, the government-[controlled] area is getting smaller and smaller,” he said.

Taliban forces have also launched military offensives aimed at encircling government-held territory in many parts of the country. To prevent increased violence, U.S. negotiators are scrambling to secure a peace deal between the militants and the Afghan government ahead of the withdrawal, but have not announced any progress.

Afghan Interior Ministry spokesman Tariq Aryan said the country’s “highways are important for us, and we have taken serious measures to suppress the enemy on them completely.”

He said some government checkpoints that were deemed “not effective” have been removed in recent months and the forces transferred to larger, nearby bases for “strategic” reasons. He acknowledged that the Taliban has a presence on Afghanistan’s roadways, but he said the militants are “scattered,” aiming only to intimidate and extort travelers.

The United States prioritized Afghanistan’s highways as key to both security and economic stability after the 2001 invasion and spent nearly $3 billion repairing them. Now, they are some of the most dangerous parts of the country for many Afghans.

“It’s all Taliban country now,” said Muhamadi, a 24-year-old taxi driver who has been shuttling passengers almost every day between Kunduz and Kabul for the past three years. Muhamadi, who, like many Afghans and others in this report, goes by a single name, works at one of the main stations in Kabul for passengers looking to head north.

Most Taliban checkpoints along highways in Afghanistan are no more than one or two fighters and a flag, but more than a dozen drivers say it is enough to scare away customers. Revenue has dropped by about half over the past year, they say, as most Afghans choose not to travel or those with the means opt to fly.

At a taxi station collecting passengers for the ride south of Kabul, drivers described a similar phenomenon: Taliban outposts sprouting up along roadways over the past year where government checkpoints once stood.

Nafi Pashton, a 31-year-old driver, said the Afghan troops stationed at the few bases that remain along the southern highway refuse to leave their fortifications out of fear of Taliban attacks. He said they often wave down taxis to pass provisions along to the next government outpost just a few kilometers away on the road.

“They give me food, oil, meat,” Pashton said. “It happens a lot.” Sometimes, he said, militants stop him and confiscate supplies; other times, he manages to deliver the goods to the government forces.

The taxi drivers said they and most of their passengers are not hassled by the Taliban. “They are only looking for government employees and security forces,” said Wahid, 43, who has been a taxi driver in the provinces for more than 20 years.

“The Taliban has very good intelligence,” he said, describing one of the times the fighters pulled a man out of his car. “They stopped the car, and just said, ‘You! Get out!’” pointing to a single man seated in the middle of the car without offering any explanation. After they took him, the fighters let Wahid and the rest of the car go.

Taliban spokesman Zabiullah Mujahid said the checkpoints are intended to keep “the enemy” — referring to Afghan government employees and security forces — out of Taliban territory and improve security along main roads.

All the highways out of Kabul “were unsecured, so we have posted our mujahideen [Taliban fighters] to ensure security day and night,” Mujahid said. “We are not restricting common people but are keeping watch of the movements of the enemies and their military.”

The inability of government employees to use major roadways in Afghanistan is preventing more Afghans from receiving government services. School principals in Helmand and Kandahar say more Taliban checkpoints there mean fewer teachers — who often live in urban areas — can reach schoolhouses outside provincial capitals. In Baghlan, a doctor said the checkpoints make it more difficult for him and his patients to get to his hospital.

A provincial council member in the same province, Mahbubullah Ghafari, said the increasing presence of Taliban fighters on the roads is encouraging his constituents to arm themselves. He estimates around 1,000 have done so already, many selling their livestock to purchase weaponry.

“What can our government do for us if no one is safe on the roads?” asked Mujtaba, a shopkeeper in Helmand who once drove the southern portion of the highway from Kabul every few months to replenish his stocks.

“I remember before I didn’t want to sleep for any part of the drive, it was so beautiful,” he said, recalling that he would request a seat in the front of the taxi for the best view. But the last time he made the journey by road six months ago, he purposefully sat in the middle of the vehicle and crouched down to avoid catching the attention of a Taliban fighter.

Even though Mujtaba has no ties to the security forces or the government that would make him a Taliban target, he said the fighters’ checkpoints terrify him. He has vowed never to make the trip by road again.

“During that last entire drive,” he said, “I was just thinking, ‘I’m already dead.’”