Jackie Williams, who works at Nordstrom at Tysons Corner, begins her commute home to Temple Hills, Md., from Tysons Corner. (Katherine Frey/The Washington Post)

Before Metro’s Silver Line opened over the summer, Jazmine Jenifer, 21, worked for her mother at Glamour Girls Hair Studio in Temple Hills, Md. Her job was “helping out” around the shop, she said, and her pay was “whatever my mother could give me.”

Which she realized was no way to make a living.

Now, with Metrorail extending into the relatively job-rich Tysons Corner area, Jenifer rides a bus from Fort Washington, where she lives, to the Green Line’s Branch Avenue station in Suitland. From there, she travels eight subway stops to the L’Enfant Plaza station in the core of Washington. Then she transfers to a Silver Line train, rides 14 stops to the Tysons Corner station, gets off and walks a short distance to her new workplace.

It’s an hour-plus trek in each direction, more than $12 a day in fares.

“It’s worth it,” said Jenifer, who was hired last month as a $9.25-an-hour cashier at the Nordstrom cafe in the Tysons Corner Center mall.

A look at the busiest originating stations for each of the new Silver Line stops.

“After they started the Silver Line,” she said, “I was like, ‘Okay, new opportunities.’ Because [there are] a lot of people living where I live at, they aren’t going to travel to Tysons for work. So I figured I’d have a better opportunity getting a job out here.”

With the Silver Line’s first phase creating a rapid-transit link between the Tysons area and the District — and the line’s second phase scheduled to connect Tysons to Dulles International Airport in 2018 — planners predict huge economic growth in coming years.

They envision dozens of new high-rise office buildings near the four Tysons Silver Line stations and an influx of corporate tenants offering thousands of well-paying jobs.

In the meantime, a surprisingly large number of long-distance commuters are using the Silver Line to get to Tysons, as well as to the Silver Line station at Wiehle Avenue in Reston, according to an analysis of Metro ridership data by Ben Ross, president of Action Committee for Transit, a public transportation advocacy group.

And, like Jenifer, many of those riders travel to Tysons and Reston from areas where jobs are harder to find — from neighborhoods east of the Anacostia River in the District and from parts of Prince George’s County inside the Capital Beltway, Ross’s analysis found.

Louis Lang, 44, a stock clerk at a store in Tysons Corner Center, has been commuting from Suitland since he landed a job in the mall last year. He boards a train near the southern end of the Green Line and follows the same route to Tysons that Jenifer takes.

Before Silver Line service began in July, Lang would transfer to an Orange Line train at L’Enfant, then ride to the West Falls Church Metro station and catch a bus to Tysons. Like several other commuters from Southeast Washington and Prince George’s who were interviewed recently, Lang said he wishes he could live in Tysons.

But he can’t swing it on a stock clerk’s wages.

“You’d need a high-paying job that you can actually afford your bills with,” said Lang, who lives alone in a $900-a-month Suitland apartment and has two daughters. Gesturing to the new skyscraper headquarters of a satellite communications company near the Tysons station, he said: “It would take you having a tech job or something. I mean, the average rent out here is $1,800, I think. There’s no way you can do that.”

As for Jenifer, she lives rent-free with her mother and stepfather. “Until I find a job closer to home,” she said, “I’ll keep on riding the train.”

Ross, author of the book “Dead End: Suburban Sprawl and the Rebirth of American Urbanism,” lives in Montgomery County and said he enjoys fiddling with numbers, especially numbers related to public transportation.

With computer help, Ross said, he studied reams of Metro ridership data covering five days and nights starting Monday, Sept. 8 — thousands upon thousands of numbers, including the passenger entry and exit figures at each of the rail system’s 91 stations, recorded at 15-minute intervals, and the origins and destinations of every trip.

“Just to see what patterns I could find,” he said.

After “many, many hours” of work, Ross said, he noticed that a sizable number of passengers getting off at the five new Silver Line stations that week had begun their trips in Southeast Washington and Prince George’s. He narrowed his focus to the morning rush hours, defined by Metro as 5 to 9:30, and calculated daily averages.

Of the average 2,987 Silver Line riders who exited at the McLean, Tysons Corner, Spring Hill, Greensboro and Wiehle Avenue stations each morning, 432 of them, or 14 percent, had started their rides at 20 stations in the Anacostia area and Prince George’s, Ross discovered. Of the 432, he said, 126 got off at Tysons.

“The most common motivation for Silver Line riders from the east side is surely economic necessity, as most board at stations that draw riders from less affluent neighborhoods nearby,” Ross said on the Greater Greater Washington blog, where he posted a summary of the data. “These ridership figures are a reminder of how painful it is when low wages meet land use policies that separate jobs from affordable housing.”

For instance, here was Dexter Clarke, 24, a cook at BJ’s Restaurant and Brewhouse in Tysons who rents a small house on Ridge Road SE in the District: “Man, look at this place,” he said as he hurried past a new steel-and-glass luxury apartment tower next to the mall. He scoffed and shook his head, continuing on his way to work.

“I don’t even want to look,” he said.

If the Silver Line spawns a vast Tysons skyline of new office, hotel and residential buildings in the years ahead, as economic development officials anticipate, then the flow of service workers into the area will become a massive tide, said Michael Caplin, executive director of Tysons Partnership, an association of business leaders, homeowners, county officials and others who are monitoring the redevelopment.

“There’s going to be just millions and millions of square feet of space needing to be maintained,” Caplin said. “And traffic in the hotels in this area is driven by the business community rather than vacationers. So when business really kicks up, there’s an increase in business travel and a need for more service staff at all the hotels.”

Ross acknowledged that not all of the current long-distance commuters necessarily work in lower-wage jobs. And not all are annoyed by their time-consuming rides.

“I get up at 6 and leave out of my house about 6:40,” said Charmel Tate, 31, who lives near the Green Line’s Naylor Road station in Temple Hills and works as a surgical counselor at See Clearly Vision, an ophthalmology practice in Tysons. “I get on my train about 7, and it takes me about an hour to get out here. So I don’t mind.”

She’s happy to be working. Her former employer, a vision-care center in downtown Washington, closed last year, and she spent six months looking for a job before finding one in Tysons in March. She said it’s worth the long commute and $11 or so in daily fares.

Smiling, she said, “You know, I’ll just read, listen to my music.”

Ross’s findings came as no surprise to Gerald L. Gordon, chief executive of the Fairfax County Economic Development Authority. “Because historically, we have imported almost half our workforce,” he said. “I think the current figure is either 47 or 48 percent of the people who work in Fairfax County come from outside.”

For years, as planners have mapped the hoped-for transformation of Tysons from suburban sprawl into a quasi-urban community of high-rises and walkable green spaces, they have wrestled with the question of how to provide affordable housing for the legions of service workers who would arrive with the growth, Gordon said.

“Even nurses and police officers and teachers can’t afford to live close in,” he said, adding that a solution to the problem of “workforce housing” remains elusive.

“But the fact is, they have always been able to get here, whether they’re driving or they’re taking the bus,” he said. “Now, if they can get here on the Metro in 70 minutes, probably that’s better than their drive time from east of the Anacostia.”

That’s about how long it takes for Jackie Williams to commute from Temple Hills: a bus to the Naylor Road station, a Green Line train to L’Enfant, a Silver Line train to Tysons and a short walk into Nordstrom, where she has worked for about a year in the store’s call center, answering customer queries by phone.

Williams, 27, lives by herself in a $1,055-a-month apartment, “and that’s with all utilities included,” she said. A comparable place in Tysons, without utilities included, “would be too expensive for me. . . . I’ve looked into it. I would literally have to have a roommate, and I don’t particularly care too much for roommates.”

So she rides. And rides. And rides.

“Sometimes, I don’t even realize how far out I am on the Metro until I look up in a while, and I’m like, ‘Oh, wow, I’m almost there,’ ” Williams said. “Some people don’t like it, but it’s all right with me. I mean, honestly, it gives me more time to sleep.”