In many of the region's outer suburbs and along the fringes of more established counties such as Fairfax, it's not just school-aged children who are taxing local resources. Hidden behind the facades of those new subdivisions is another population boomlet seeking services: grandma and grandpa.

Call it the graying of suburbia. Some elderly residents have lived in the area for decades, but others are recent arrivals who have relocated to be closer to their adult children. Once here, many feel isolated. With their cars sold, their driver's licenses lapsed and their children working miles away, many of these elderly residents find themselves stranded, with no way to escape their cul-de-sacs.

Social service agencies say they're trying to help, but resources are already stretched thin, leaving little extra to pay for senior centers and the transportation networks needed to help these older residents navigate the outlying suburbs.

Steven Johnson, a 38-year-old pilot who lives in Vienna, said he had no idea that transportation would be such a problem when he moved his parents, Mae and Ralph Johnson, from Los Angeles to Loudoun County two months ago.

"I was hoping that public transportation would give them the freedom that they're looking for, and it hasn't," he said.

Local agencies on aging say they're receiving more requests for services from people such as the Johnsons who have relocated here to be near family.

Working the phones at Elder Choices, a Loudoun County referral service, Mary Jane Barney-Butler has noticed an increase in calls from these "imported" seniors or their relatives. She's even started keeping tabs--50 such calls most weeks, she said.

Typically, the callers say things like " 'I'm bringing Dad tomorrow and I don't know what to do,' " she said. "They're trying to do everything."

Nationally, census records show the 85-and-over age group growing faster than any other slice of the population, a boom that, locally at least, extends to the 65-plus corps, which is expanding at a rate faster than that of the general population.

Although demographers attribute much of this trend to better medical care, officials in Washington's outlying regions also note an increase in families importing their aging relatives. Precise numbers for this are nonexistent, so officials are relying on anecdotal information and general surveys for their estimates.

In one such survey, a 1990 tally of Fairfax residents 65 and older, 10 percent said they had lived outside the county within the last five years. A similar survey last year found that 27 percent of respondents had moved into the county within the last five years.

Sixty-eight of 160 people registered at Fairfax's newest senior center, in the county's westernmost Sully District, said in a questionnaire that they had recently relocated from out of state to be near their children, according to center director Kris Miller.

The number of imported seniors also is on the rise in Prince William, said Lin Wagener, director of the county's Agency on Aging. With the county's large military presence, seniors often experience another level of isolation if their children are in the service and get transferred out of the area.

"It's one of the saddest things that we see," Wagener said.

Transportation for seniors is the most pressing growth-driven problem, social workers say.

Officials in Loudoun try to arrange rides to doctor appointments for seniors, using a hodgepodge of methods, including county-financed buses, vans and taxis. But the number of such trips has been rising steadily, from 10,000 last year to a projected 12,900 in 2000, officials say. The program is perpetually short of cash, they say, and on occasion they've had to limit rides to the frailest and most severely ill.

Laura Neufeld, 81, who moved to Loudoun from Florida five years ago to live with her son and his wife in Broadlands, is typical of those seniors needing transportation.

Neufeld no longer has a car. Her son works and her daughter-in-law is taking real estate courses, so Neufeld must depend on a complicated schedule of rides on the county's shuttles to get where she needs to go, principally to her doctor.

She hasn't joined a nearby senior center for fear of disrupting her fragile transportation setup, and she's resigned herself to not visiting the public library: "If there was a bus I could take, even if I had to walk a block to the bus stop, if I could come back when I wanted, I would take it to the library."

Instead, Neufeld spends much of her day alone with the family's parrot, two Dalmatians and her memories. "What to do with all those hours, I don't know," she said.

Many elderly who move to outlying suburbs have no idea how isolated their new life will be.

Mae and Ralph Johnson thought they'd be able to use county shuttles for the elderly when they moved to Ashburn in September. The couple sold their Oldsmobile when they left California--a decision Mae Johnson, 70, who has bone cancer and needs biweekly treatments, regrets daily. Walking is painful for her, and the shuttle bus stop is a long block away.

Their son Steven, daughter-in-law Kathleen and 9-month old granddaughter live in Vienna, but Mae hates to bother them for rides. "They are so busy, and then [the baby] is on her own little routine."

Instead, Mae frequently pays $14 for the six-mile cab ride to her doctor's office. A neighbor in their apartment community, 62-year-old Ray Ambers, still drives and often gives Ralph, 77, a lift to the grocery store or drops Mae off at her doctor's.

After transportation, the other pressing need for the suburban elderly is senior centers, places to break the monotony and isolation.

At Fairfax's new Sully Senior Center one recent day, three women indulged a shared passion for pinochle and a penchant for telling how they've managed in new surroundings.

"A lot of us suffer not so much from depression as from lack of involvement. We get to talking here. It's better than TV," said Joan Malloy, 67, who left Long Island to share a Chantilly town house with her daughter and be near her son in Fairfax Station.

But the two county-funded buses that bring people to the Sully center aren't enough to provide rides for everyone who wants them, and the center now has a waiting list of dozens of names.

"Today it seems like the kids worry that their parents aren't where the kids can see them, so they ask parents to move in and parents do," said Miller, the center director. Parents "don't realize until they've made the move how much they miss their home and all their friends, and it's a lot to give up. There's quite an adjustment period."

CAPTION: Araxi L. Hovanesian, left, Peggy Chang, center, and Mary Campbell exercise in a daily program at the Sully District Senior Center.

CAPTION: Zena Spasaro, left, reacts to Araxi L. Hovanesian's winning bingo card at the Sully District Senior Center.