The Arlington County board voted last week to take down experimental traffic diverters to the Ashton Heights neighborhood and to reject permanent barriers after an emotional, three-hour long session where neighbor argued against neighbor, with both sides invoking truth, justice and the safety of little children and old ladies.

The board vote conceded a failure in a traffic control plan designed to divert large amounts of commuter traffic away from the residential neighborhood, a plan which opponents said had just channeled the traffic into the neighborhood through other streets.

But the board affirmed its intention to try to find some other means of stemming the commuter traffic that flows through the neighborhood, a close-in bedroom community of about 1,500 households, bounded by Wilson Boulevard and North 10th Street on the north, Arlington Boulevard on the south, Irving Street on the east and Glebe Road on the west.

"I think it was a valuable experiment but it caused a lot of concern and inconvenience," said board member Ellen Bozman. "It didn't work, but that doesn't mean there is not some other solution," she said. County transportation officials said they would put up stop signs along streets which had been blocked with barrels during the experimental traffic diversion program.

The barrels which symbolized the neighborhood turmoil of the last three months are 55-gallon oil drums, freshly painted in white and black stripes, and rolled across two intersections in Ashton Heights. County manger W.V. Ford had recommended making one of them - a barrier at North Oakland and 4th Streets - permanent, but the board turned down the recommendation.

The barrels were put up to divert commuter traffic from 4th and 5th streets, short cuts which had been used frequently by commuters to avoid major arteries during rush hours. Some of the traffic was diverted to major arteries, but other traffic went streaming down unbarricaded residential streets, witnesses said.

"We have not stopped the commuters. They find ways like water through a sieve to go through," said board member Dorothy Grotos. "But during the day we have stopped the neighborhood," he said, after witnesses testified that the barricades complicated their own travels through the neighborhood.

Saturday's hearing followed two apparently stormy sessions of the Ashton Heights Civic Association, which almost doubled its membership and dues when residents packed into a meeting to vote "no" on the traffic diverters.

The group voted to oppose the barriers both times, first on Jan. 26, and again the night before the hearing.

The sides lined up again on Saturday. Before the barriers, said Peter Scott, who lives on North 4th Street, the street was unsafe."We lived on what amounted to a uperhighway," he said. Other proponents of the barriers said that before they were installed, children who lived on the heavily traveled streets were in peril.

On the other side, a woman who lives on a narrow street to which traffic was diverted said that pedestrians are now in danger there, citing instances of children and elderly women walking down the street as proof of the potential problem.

The barriers were installed last October by the county's transportation department after consultation with the civic association, which then supported the plan. The plan is part of a long-range county goal emphasizing neighborhood preservation over commuter convenience.

Generally, people who lived on the street from which traffic had been diverted spoke in favor of retaining the diverters, with residents who lived on other streets opposing it. A handful of spokesman from other neighborhoods, who said they feared that setting aside the traffic barriers might be a blow to the idea of neighborhood preservation, also spoke in favor of retaining the obstacles to traffic.

"We're fighting to use the streets we paid for," said one opponent of the barricades."If the barriers didn't work on a test basis, why the hell should they work on a permanent basis?" she said.

Contributing to this story was special correspondent Alexander M. Sullivan.