The yellow school bus lumbered through the darkness. At a street corner in Reston, the driver opened the doors for his first passenger, a lanky 16-year-old still rubbing the sleep out of his eyes. It was 6:35 a.m. and the beginning of another 22-mile trip for the driver and the 10 school children he would pick up along the way.

An hour and 40 minutes later, at 8:15, the bus finally arrived at its destination in Vienna, unloading its passengers as the morning sun began to take the chill out of the fall air.

The ride was not part of a special field trip, but merely the first half of a daily ritual that these 10 physically,mentally or emotionally handicapped children sit through on their way to and from school at the Kilmer Center, a special education center in Vienna.

The long ride, say parents of the handicapped children in Fairfax County, is not unusual and is evidence of a growing problem: The county is unable to meet the transportation needs of its handicapped students.

"All I could do was laugh when I was watching the news last year and heard a woman complaining that her child could no longer walk to school and would have to take a bus because her neighborhood to school was closing," said Ellen Areman, the parent of a handicapped child. "She wasn't talking about 20 minutes, half an hour or an hour, but riding the bus for five to 10 minutes. 2

" . . . Our kids are riding all over the county, driving for hours on icy roads in the winter. All we want to do is get them to school in a relatively reasonable period and in one piece."

Parents contend that not only are the long rides exhausting for the children, but they violate federal laws requiring comparable services for handicapped and nonhandicapped children. Recently, several Fairfax parents filed complaints with the state Education Department and the state Developmental Disabilities Protection and Advocacy Office, which oversees enforcement of state and federal laws regarding the handicapped.

Last month, the disabilities office requested an explanation of the long Fairfax rides. School officials say they are studying the request and expect to reply soon.

County transportation officials say that under ideal conditions no handicapped student should be on a bus for more than an hour each morning and afternoon -- a little more than twice the average 25-minute ride for nonhandicapped students. But, say the officials, a severe shortage of buses and a large territory to cover make that goal increasingly unattainable.

"The solution to the problem is simple: We need more buses," said Frank Dixon, assistant director of transportation for the Fairfax schools. "Right now, we could use at least 20 more buses to (make a) dent (in) the problem. We can only do so much with what we have."

The county has 137 buses for about 2,400 handicapped children who are picked up at their homes and taken to more than 60 education centers around the county. That is a ratio of one bus for about 18 students, down from 1975 when the county had 80 buses for about 600 special education students, or a ratio of one bus for about 7 1/2 students. Thus, the number of students using the buses has quadrupled while the number of buses has not even doubled.

"It is only logical," said Dixon, "when you keep increasing the number of kids, without proportionately increasing the number of buses, the time spent on the buses will increase also."

Last year, Dixon said, the county ordered seven more special education buses, but because of a strike they are not expected until at least November.

In Arlington, 16 lbuses serve 400 handicapped children, about one bus for every 25 children and in Alexandria 10 buses serve 122 special education students, about one bus for every 12 children.

But Fairfax officials say the major difference between their jurisdiction and Alexandria and Arlington is the size of the county -- nearly 400 square miles -- and the number of students they must serve.

The average route for handicapped students in Fairfax is about 20 miles, according to Dixon, and the longest ride is 39 miles. As a result, say county officials, the average ride for handicapped students is about an hour, but can be much longer.

"We have one route in the county (running to the Quander Road Center in Groveton) that if you drove it straight through without picking anybody up, it would take at least an hour in traffic," said Dixon.

By comparison, the longest route in Alexandria is eight miles and takes about 40 minutes. In Arlington, the longest route is about 17 miles and takes about 50 minutes. The average ride in Alexandria is about 25 minutes, and in Arlington, about 35 minutes, according to school officials.

Everyone -- parents, transportation and school officials -- agrees more buses are needed. But there seems to be little agreement on whether the schools can afford additional buses right now.

"We're talking about folks who need all the help we can give them," said Fairfax Superintendent L. Linton Deck. "We are looking at all the options but we just don't have the resources readily available."

Transportation official Dixon said his office has requested 33 additional special education buses for next year. A 64-passenger bus costs $28,000, Dixon said; a 34-passenger bus costs $23,000. Handicapped children generally ride the smaller buses, he added.

"For the first time in years, the school board seems to be sincerely interested in the problem of transportation for the handicapped," Dixon said. "In past years we would request additional buses and we would be turned down flat without any explanation."

School board member Carmin (Chuck) Caputo echoed Doxon's concerns and insisted that the board would not ignore the problem when the budget process begins for the next fiscal year.

"We've got to cut back on this ridiculous situation of children riding the bus two to three hours a day," Caputo said. "It's not something we're going to let slide by."

Ironically, the national reputation of special education programs in Fairfax may have contributed to some of the problems. School officials say some families, attracted by the quality and variety of special education programs, have moved to Fairfax primarily so their children could be in those programs. Five years ago, according to special education director Dan Links, the county had about 1,600 children in its special education programs. When school opened this September, he said, that number had more than doubled to about 3,400.

While school officials may be optimistic about reducing the problem, parents of the handicapped children expect no quick solution.

Ellen Areman's 8-year-old daughter Stephanie was handicapped by a stroke four years ago. Areman has asked school officials to move Stephanie from a special education program more than 12 miles from her home to a regular classroom at her neighborhood school.

"One of the main reasons we moved to Fairfax was that it had such a wonderful reputation for its handicapped program," Areman said. "But I just can't go through another year of this -- waiting for the bus to come, wondering what time she will come home, whether she will get to school on time."

"I'm lucky my child can function in a regular classroom, she can walk, she can read. But there are some children who have no place else to go but to the special centers far from their homes. How can you expect the children to do anything when they get home after such a long ride? They're only little kids."