PLAYA DEL CARMEN, Mexico — Twisted tree trunks were plowed into high piles along a slash of freshly cut jungle, like thousands of discarded matchsticks as far as the eye could see. This path of deforestation in southern Mexico was recently cleared to make way for an ambitious government project: the Maya Train railway.
Pitched as a means to reinvigorate the country’s poorest region and one of its least connected, the Maya Train is one of President Andrés Manuel López Obrador’s crown jewels — a project on which he has staked his legacy.
A “great detonator” for the south’s economy, a government spokesman for the lead agency called it.
But the cargo and passenger train line, expected to be nearly 1,000-miles long, is shaping up to be the president’s most contentious undertaking yet. At the very least, it is wildly over budget, may not bolster the economy like it was promised to, and will be subsidized by taxpayers for years to come, analysts and project officials say. At worst, it could collapse into the ground because of rushed construction, government officials and project contractors warn.
Despite many concerns raised by officials, advisers, scientists and even the rail’s supporters, Mr. López Obrador has refused to slow the project down, hellbent on inaugurating it before his term ends in 2024.
It is the largest of some $45 billion worth of major infrastructure projects that the Mexican leader has vowed to deliver, but that so far have yet to produce the economic or political benefits he promised.
The president “is not someone who listens,” said Gemma Santana Medina, a consultant on the project who resigned last year after criticizing the planning. She is one of several current and former officials who said the president has not heeded their expertise.
“His is truly a dictatorial vision,” she said.
The most contentious segment of the train — Section 5 — will link the famous white sand beaches stretching from Cancún to Tulum in the Yucatán Peninsula. To minimize deforestation, construction was initially planned along a highway. But now it will snake through the second-largest jungle in the Americas, inhabited by endangered jaguars. The tracks will run above the world’s longest underground river and over hundreds of unexplored caves that have been found to contain ancient ruins from the Maya civilization, the project’s namesake.
Amid mounting domestic pressure, Mr. López Obrador invoked a national security decree in July to restart work on the Maya Train and shield it from scrutiny, after a court injunction halted construction over environmental concerns. A district court judge also ruled in the government’s favor this month to continue the work.
The president said the decree would “provide continuity to a very important public work” that had been halted by “the pseudo-environmentalists financed by the United States government.”
The delays had cost the government time and money, Mr. López Obrador said, and would no longer be tolerated. Section 5 did not plow through the jungle, he added, dismissing it as nothing more than shrub — contrary to ecologists’ assessments, including one who advised the project.
The government also fired the civilian contractors who were building Section 5 and put the military in charge, further blocking it from public oversight. The Mexican military is not required to publicly release information on any project it undertakes, unlike contractors.
“He is abusing the national security decree to push through this project that has been murky from the beginning,” José Urbina Bravo, a biologist, said of the president.
Mr. Urbina and others involved in the injunction say they initially supported the Maya Train, hoping it would help revitalize southern Mexico’s hobbling economy. They say they only opposed the project when, in February, the government moved Section 5 to the jungle without doing legally required environmental studies. That’s when they filed a lawsuit, prompting the injunction to stop construction.
From the beginning, the Maya Train has been complicated by a president obsessed with delivering numerous large-scale legacy projects during his six-year term.
Government officials and engineers working on the plan said it needed up to 15 years to plan and execute, in line with railways of a similar size built elsewhere in the world. Instead, Mr. López Obrador gave the project four years.
When he unveiled the plan in 2018, he said it was more than just a railway. The train would link southern Mexico’s main cities, each station creating a new urban center with sprawling commercial spaces that would be rented out to fund the project and boost the economy.
The president promised the railway would be constructed in a cost-effective manner to save taxpayers a hefty bill, and would be built on existing rail track or road to preserve the Maya Forest’s fragile ecosystem.
“Not a single tree” would be cut for the project, Mr. López Obrador had insisted.
But two years in, few of those pledges have held.
The government has already surpassed its budget without completing any of the planned seven tracks. The train could cost up to $20 billion, the president recently announced, nearly three times more than the initial estimate.
More so, the project’s development ambitions have been scaled back in order to finish before the president leaves office, according to a senior government official close to Mr. López Obrador who asked for anonymity to discuss the plans freely. The railway will no longer run through Mérida, the region’s largest metropolis and economic hub, or Campeche, another major urban center, a setback for the government’s promise to connect the region.
Many of the commercial spaces that were designed to complement stations and help fund the Tren Maya’s future operations have also been quietly cut, according to the senior official. Without them, the train will likely be saddled with debt for years to come, the official and a contractor on the project warned.
A spokesman for Fonatur, the government agency overseeing the Maya Train, challenged these assertions and insisted the train would spur growth in the peninsula and turn a profit.
“President Andrés Manuel sees the Mayan Train as an important engine of economic development that seeks to close inequality gaps,” said Fernando Vazquez, the spokesman.
He added that the train would bring visitors to other parts of the south, spreading tourism and therefore development, though many have argued that beachgoers who visit places like Cancún often want to stay in their hotels. Mr. Vazquez added that the government would also invest in development projects like schools and housing along the railway.
While the government did commission economic and environmental studies, the project has changed so many times that those findings are no longer relevant, according to officials working on the project. Such modifications, like changing the route seven times, were undertaken to speed up construction to meet the 2024 completion deadline, officials explained.
Initially the railway was supposed to be about 90 percent privately financed, attracting commitments from major Wall Street banks including BlackRock and Bank of America. Now, Mexico’s central government will foot most of the bill after the president decided that the interest rates investors were offering were too high.
Even some who at first supported the project — including several architects, engineers and project officials — are starting to have doubts.
The train is “necessary” to develop the region, said Carlos Veloz, an urban planner in Cancún. But if the train is not planned correctly, it could “create more inequality, more problems,” he warned.
“It has to be done well,” he added.
Now, there are major safety concerns hanging over Section 5.
After hoteliers complained about the traffic the construction was causing along the highway, Mr. López Obrador agreed to move the route to cut through about 70 miles of the Maya Forest, according to the Fonatur spokesman.
The new route stretches across the soft limestone of the Maya Forest where the natural beauty of the area could prove dangerous, geologists warn. Thousands of caves riddle the naturally eroding limestone terrain like Swiss cheese, yet trains weighing up to 217 tons could cross directly over this unstable ground.
A nearby highway, built on similar land, collapsed from the weight of cars and construction in at least two sections in recent years.
“Time and studies must be done well in advance,” said Zenón Medina-Domínguez, the former head of the College of Civil Engineers of Yucatán, who studied the ground ahead of the construction of Cancún airport decades ago on similar terrain.
“Our job is to work with difficult ground and find ways to build on it,” he said, adding that the airport terrain studies took up to six months. In contrast, the government started razing several miles of the jungle before doing any studies.
Also at risk are undiscovered archaeological relics.
Explorers who found some of the oldest human remains on the continent in an underwater cave near Tulum said it took them months of dangerous diving to discover them. They worry about what could be destroyed as the government rushes to fill the caves with cement or pylons to build. The ancient Maya saw caves as openings to the underworld and often left artifacts in them.
Yet the president remains determined about his deadline, despite the warnings.
“Anyone who knows the area, scientifically speaking, is concerned about where the train will pass: over one of the largest caves and underwater systems on the planet,” said Gerardo Ceballos, an ecology professor at the National Autonomous University of Mexico and a member of the U.S. National Academy of Sciences.
Mr. Ceballos was an early consultant to the government on the project. He now has doubts over the recent detour into the forest.
Referencing the Mexico City metro collapse last year, which killed 26 people and wounded scores more because of rushed construction, Mr. Ceballos said, “It will collapse.”
Oscar Lopez contributed reporting from Playa del Carmen, Mexico.