In wheel chairs, in mobile beds and in the arms of their parents, several Fairfax County children wait at their front doors every weekday morning to be loaded onto Bus 210.

In the language of educators, these children are multiple-handicapped - they have mental and physical impairments. Some cannot walk or talk, use their hands or even hold their heads up straight. Some are deformed, with limbs that are atrophied or askew. Some have reached adolescence, but are the size of pre-schoolers.

But they all can smile when the bus arrives. Every week day, the bus performs a small miracle by bringing these children a public school education.

At 9 a.m. sharp, Bus 210 pulls up alongside 11 other special education buses at the Lincolnia Center for the Multiple Handicapped, across from Landmark Shopping Center, and 96 seriously handicapped children from throughout Fairfax County begin a five-hour school day.

At best, the children, aged 5 to 21, are taught to be independent by learning to walk, talk, dress and feed themselves and use the toilet. At the very least, they are taken from the isolation of their homes - sometimes the only world, besides the school, that many of them know.

The 1 1/2-hour bus ride, the average length of a trip to the center, becomes a significant part of the school experience.

Ginny Anderson, 6, is one of the [WORD ILLEGIBLE] students picked up each morning on the route that zigzags across Rt. 1 just south of Alexandria.

The bus parks in front of the [WORD ILLEGIBLE] the Woodly-Nightingale Trailer Park where Ginny lives with her grandparents. Arcemus and June Anderson. Bus driver Roberta Fowler, herself the parent of a severely handicapped son, and her aide, lower an automatic lift built into the full-sized yellow school bus that normally can carry 54 non-handicapped students. They help June Anderson wheel Ginny's mobile crib onto the platform of the lift.

The three women talk about how Ginny spent the night and then the lift whirs up. Ginny's crib is rolled to the back of the bus and bolted onto brackets where the seats have been removed.

Ginny was born with an open spine that stunted her growth, but caused her head to overdevelop. She looks like an infant in her bundle of blankets and a parka; she is the only student on Bus 210 confined to a bed. The sunlight shining through the bus window makes her drowsy, but for a while her eyes follow passing treetops and telephone poles.

Before enrolling in Lincoln Center tree years ago, Ginny spent most of her time in her bedroom or on the living room couch where she listened to radio and television.

"She's always had plenty of attention all right, but we're not trained to teach her everything she's able to learn," her grandmother said. "She perks up when I lay her clothes out in the morning; she knows that means the bus is coming."

At Lincoln Center, whih opened in 1974 as the only public school for the multiple-handicapped in Fairfax County, Ginny is learning to form complete sentences and taking physical therapy that one day may help her to sit up on her own.

The bus stops again and the lift comes down for Tina Entwisle, a 19-year-old girl confined to a wheel chair, who immediately engages the bus driver in halting conversation. Two stops later, in the Fairhaven area, Kevin Crisp, 11, is picked up. His wheel chair is bolted in next to Tina's and the two begin an obviously standard-routine. Tina nudges Kevin, tries to get him interested in her stuffed buffalo. Kevin, who cannot talk, responds with a smile that stretches from ear to ear.

Kerry Washer, 8, is the last student to board the bus. It is difficult for the fragile, pretty girl to muster enough strength in her limp body to hold up her head, but at Fowler's urging and fascinated by the lure of passing sights, she raises it from time to time during the remaining 20 minutes of the ride.

None of the guardians who put the children on Bus 210 every morning complain about the lengthy bus trips that result from time-consuming door-to-door stops and the long distances to the center from the edges of the county.

"Just to look out the window makes Kerry struggle to hold her head up," says her mother, Carol Washer of 6413 Willowood Lane. "The bus gives incentive for her to try."

David Kidwell, supervisor of special education transportation for Fairfax schools, expects the long bus rides to be shortened soon. At present, he says, the addition of one child on a bus adds 20 minutes to a trip.

Next year, however, the district will add 15 buses to its fleet of 129 which serve more than 1,400 special education students in the county. (Children who do not ride the 12 buses for the multiple-handicapped attend special programs at schools throughout the county). The additional buses and the opening of two new centers for the multiple-handicapped in the next two years are expected to reduce travel time to a maximum of an hour. Last year, travel time to Lincolnia Center on some buses exceeded two hours.

The need for costly mechanical equipment and an aide to accompany each bus, which carries a maximum of only seven children, are factors in a $6,646 it costs annually to educate a child with multiple handicaps. The cost is four times more than the $1,650 it costs to educate a non-handicapped student in the county, according to Daniel Link, special education researcher.

Recent Virginia and federal laws view education of the multiple-handicapped as a right, equal to that of all children to receive "appropriate" education.

"Basically the law means that the parents of these children are not forced to go out and sell fruit cakes door-to-door to give their kids an education," said Lincolnia Center principal Joan C. Gendreau."It means that education is not a privilege, but a right for these kids."

Gendreau formerly directed a private cooperative school for multiple-handicapped children, which had an enrollment of 40 to 60 students a year. Since 1974, under the public school system, Lincolnia Center has had an enrollment of twice as many children, most from Fiarfax County.

Gendreau said she believes most multiple-handicapped children in the county are being reached by the center or by classes atthe Northern Virginia Training Center, a state institution for the menatlly handicapped.

"Generally these youngsters can do much more than their parents expect from them," Gendreau said. "It's a matter of constant supervision to show them to use what they have.

A new center for multiple-handicapped children and moderately retarded, trainable children will open in September at Kilmer Intermediate School near Vienna. A similiar center will open in September 1979 at Key Intermediate school in Springfield. The Lincolnia Center will be phased out when Kilmer and Key, which are more centrally located, are in operation.

One problem the school district has not solved is aiding severely handicapped adults. When severely handicapped children reach age 22, the bus service ends. Further training is not required by law and few nona-institutional facilities exist for multiple-handicapped adults.

"The alternatives now are remaining i home care or entering an institution," Gendreau said. "Some of our youngsters are facing, that situation very shortly now. If nothing else, being out has improved the quality of life for most of them. It has given them something to get up for and go to."