Five Prince William County families have dropped their lawsuit in federal court in Alexandria contesting the county School Board's decision to bus students 18 miles across the county to balance numerical enrollments at two high schools.

Richard V. Moraski, one of the parents from the county's Montclair section who brought in the suit, said that the decision to end the case came after U.S. District Judge Richard L. Williams dismissed last Friday the parents' argument that busing would diminish the value of their homes and deprive their children of a full education.

"He dismissed outright our strongest claim," said Moraski, who added he became more discouraged when Williams told defense lawyers for the board that if they came to court with additional information he would consider dismissing the remaining complaints against the board.

"We saw the writing on the wall," said Moraski.

Moraski, the president of a legal defense fund that raised $12,000 to fight the board action, said he is going to consult with other families about whether to take other steps to stop the busing.

The decision to drop the lawsuit, which the judge approved in court Wednesday, ended a two-year effort by some families from Montclair to prevent the board from busing high school students who live in the eastern part of the county to a high school about 18 miles from their homes. The case was brought as a class action in behalf of all families affected by the busing plan.

Joseph Dyer, the school system's attorney, said the parents' decision was a "complete vindication of the School Board."

But, David J. Fudala, the families' attorney, said, "Certainly we didn't drop the case because we thought the School Board was right."

The board decided in December that children entering high school from the Montclair area in the county's rapidly growing I-95 corridor would have to enroll at Osbourn Park Senior High, just outside Manassas. The students had previously been assigned to the nearby Potomac High School.

Potomac enrolled 1,838 students last September, well above its 1,650 capacity. Osbourn, with a capacity of 2,183 students, enrolled 1,578. The busing plan, to go into effect next month, would bring enrollment at Osbourn to 1,610 and at Potomac to 1,816.

Associate Superintendent Richard Chapin said the school system will go ahead with busing plans as scheduled. "We're going to make sure all the children from the Montclair area have a good education as we will for all children attending Osbourn Park," said Chapin.

Moraski said he didn't want to enroll his 14-year-old daughter at Osbourn because a 20-mile bus ride would prevent her from participating in after-school activities. But Dyer said students can catch a special late bus home.

Moraski, 39, said he had put his house up for sale so he can move to a Potomac High attendance area, where he says all his daughter's friends live.

Ann Bennett, 37, another Montclair parent who joined in the suit, said parents affected by the board's decision are "extremely distraught" and some have put their homes up for sale or for rent.

"I'm scared to death to have my child ride 40 miles on roads that have been written up as the most dangerous in the state," said Bennett, whose 14-year-old son will be bused to Osbourn Park.