In a bustling corner of West Virginia, a 110-year-old railroad regularly delivers limestone from a quarry to a factory where Clorox uses it to make kitty litter.

The railroad, Winchester & Western, is small, but it reveals the economic and environmental benefits of moving freight by rail.

One delivery by the kitty litter express, a service that started three years ago, replaces 48 truck journeys, a relief to the busy roads around Martinsburg, where the factory is. The train emits far lower amounts of greenhouse gases than trucks would, helping Clorox to meet its environmental goals. The company also says the rail service costs less than trucks.

“It is one of the most powerful tools we have for the community,” said Doug Long, Winchester & Western’s general manager and a native of Martinsburg, his voice louder than most because of the years he has spent riding locomotives.

Mr. Long said other companies had set up plants in the area because of the logistical advantages offered by the railroad, which is hauling over a third more freight than it was in 2020.

Now, much larger railroads want to make similar gains across the United States. Their leaders are trying to win back business lost over the years to trucking, their main rival, and they are making some big moves to do so.

Two freight giants, Union Pacific and Norfolk Southern, recently announced a merger plan that would create the nation’s first coast-to-coast rail network under a single company. They hope the deal will win business from trucks.

I visited big projects and sprawling rail yards under Baltimore’s streets, on the outskirts of Kansas City, Mo., and in Los Angeles to see how rail companies are trying to compete against trucks.

A resurgent freight rail industry would benefit businesses, the public and the planet.

Poised for a Renaissance?

Shipping goods by rail costs between 10 percent and 40 percent less than trucking, depending on the route, and the savings might in part be passed on to consumers. Shifting transportation of cargo from trucks to rail is estimated to cut carbon emissions by over 80 percent, and doing so takes tractor-trailers off congested highways and out of neighborhoods. It’s also safer to transport hazardous materials by rail.

But a railroad renaissance will be hard to pull off. Freight rail has been losing out to trucking for decades. Trucks moved 73 percent of all freight in the United States last year, up from 63 percent in 1990, while rail’s share was an estimated 12 percent last year, down from 15 percent in 1990, according to S&P Global Market Intelligence.

Trucks are typically much quicker than trains, especially on routes under 500 miles; can promise tighter delivery windows; and deliver right to the doors of businesses.

Railroads have cut costs to impress shareholders, but this sometimes hurt service for customers. And critics say the dependable profits that railroads get from transporting commodities like coal have dulled their entrepreneurial urge to find ways to better serve customers.

But Tony Hatch, a rail analyst for 35 years, said that there was plenty of business for railroads to win, and that their current leaders appeared serious about capturing it.

“I am cautiously optimistic,” Mr. Hatch said.

A 130-Year-Old Tunnel

In their fight back, railroads are focusing on an activity dominated by trucking — transporting shipping containers, the metal boxes that carry anything from produce to clothes to appliances.

Under downtown Baltimore, CSX, a large freight railroad, is rushing to complete a project in the 130-year-old Howard Street tunnel that the company expects will double the number of containers it can transport on its line from Florida to New Jersey.

The tunnel has played a notorious role in railroad history. The cost of building it helped drive its first owner into bankruptcy, and a fire burned in it for five days in 2001.

Using a robotic jackhammer designed to limit vibration, CSX is demolishing the floor of the tunnel so it can lay new tracks at a lower level. Doing that will add 30 inches to the clearance and allow CSX to stack one shipping container on top of another on the trains that go through the tunnel.

The project “is impactful to our network, as well as to the Eastern United States,” said Carrie Ann Crozier, a senior CSX executive and a fourth-generation railroader from Canada.

‘Game Changer’

Union Pacific and Norfolk Southern say their proposed $72 billion merger is all about fighting back against trucking.

“We’ve been losing share to truck,” said Mark George, chief executive of Norfolk Southern. “Volumes have been stubbornly low, and now, by coming together, we’re going to be able to get on a growth trajectory again.”

The merger is an attempt to solve the disconnect between railroads east and west of the Mississippi River.

Containers traveling from Los Angeles to New York on a Union Pacific train have to transfer to Norfolk Southern or CSX, which operate mostly east of the Mississippi, at a hub in the Midwest. That handover takes time, and each railroad puts it own business first, creating inefficiencies.

The merger, in theory, does away with those problems and will provide faster coast-to-coast service.

“That’s a game changer,” said Jim Vena, the chief executive of Union Pacific.

Mr. Vena met with President Trump in the Oval Office last week, where they discussed the advantages of having a transcontinental railroad, a company spokeswoman said.

‘Why Put the Industry at Risk?’

But the deal must satisfy the rail regulator, the Surface Transportation Board, whose rules require that mergers don’t diminish competition or lead to operational problems, something that happened after past tie-ups.

Keith Creel, the chief executive of CPKC, the United States’ fifth-largest freight railroad, said that Union Pacific and Norfolk Southern did not need to merge to offer better service, and that the deal could lead to disruptions.

“They can do more with what they have,” Mr. Creel said in an interview. “Why put the industry at risk? Why put our customers at risk? There’s not a compelling need to be able to do it.”

CPKC is itself the product of a 2023 merger of Canadian Pacific, a large Canadian railroad, and Kansas City Southern, a medium-size American one.

A new, large refrigerated warehouse outside Kansas City is part of CPKC’s plan to capture business from trucks, Mr. Creel said. American pork and other meats will are stored and inspected there before CPKC transports them in refrigerated containers to Mexico.

‘Knock Down All Our Barriers’

Rail is an old industry, and some executives are trying to put an end to practices that they say have driven away customers.

One difficulty that large railroads have is coordinating the transfer of rail cars to smaller, “short line” rail roads. The large railroad might bring the wrong number of empty cars to the short line or they might arrive at the wrong time, creating headaches for customers shipping goods.

The solution that Norfolk Southern is attempting is surprisingly simple: Microsoft Teams meetings. The company regularly holds them with the short lines to hash out what’s not working, said Stefan Loeb, a vice president at Norfolk Southern.

“It’s like, ‘Hey, let’s knock down all our barriers, and let’s get really comfortable communicating,’” Mr. Loeb said. “For whatever reason, that was not happening in the decades leading up to this.” He said the program had helped spur customers on the lines to ship 5 percent more goods.

Drones Over Los Angeles

BNSF, another large freight carrier, is using drones to tackle a problem at its 244-acre rail yard 20 miles north of the Port of Los Angeles.

Truckers delivering containers to the yard leave as many as a third of them in the wrong spot, which can delay getting them onto trains. The drones fly around the yard with technology that enables them to spot the misplaced containers.

BNSF transported over five million containers last year, more than any of its peers, according to regulatory data. Many of them move in and out of the huge ports of Los Angeles and Long Beach, Calif.

Trucks clog not only the highways around the ports but also the streets of nearby neighborhoods, where their fumes can cause respiratory illnesses. The areas would benefit if more trains than trucks carried cargo away.

A couple of big projects aim to accomplish that.

BNSF plans to spend over $1.5 billion to build a 4,500-acre facility farther inland, in Barstow, Calif., that would receive trains directly from the ports. (A regulatory environmental review of the project has yet to be completed.)

Last year, 28 percent of the containers leaving the Port of Long Beach went by rail. The port wants to raise that share to at least 38 percent by building many new rail tracks, a project that is scheduled to be completed in 2032.

“For us, this is the megaproject of the century,” said Mario Cordero, the port’s chief executive. “Well, certainly for the decades.”

‘Make Money the Right Way’

After traveling around the country looking at rail operations, I asked Robert Primus, a regulator who has sometimes questioned the rail industry’s promises, if it can win back business.

Mr. Primus, a member of the Surface Transportation Board until Mr. Trump fired him last month, had used his perch to press railroads to do more to grow.

(A White House official said Mr. Primus “did not align with the president’s America First agenda.” Mr. Primus said that his firing was illegal and that he planned to sue.)

Asked about rail companies’ efforts to win business from trucks, he praised CSX’s tunnel expansion and said BNSF’s Barstow plans were potentially “groundbreaking.”

Mr. Primus opposed the merger that created CPKC. While he declined to comment on the Union Pacific and Norfolk Southern merger, he said rail consolidation did not have a good track record of bringing growth.

“I don’t mind railroads making money,” he said. “But I think they need to make money the right way, which is growing, which is bringing on more customers, which is shipping more.”