Residents in Arlington's Glencarlyn neighborhood on the western edge of the county are fighting to get sound barriers installed along a portion of Arlington Boulevard (Rte. 50) that they say will be a source of unbearable traffic noise after the road is widened and a new interchange constructed at Carlin Springs Road.

Resident Mark Ellis, who has rallied his neighbors and civic association to support a sound barrier similar to one along I-66, said highway officials have made up their minds and refuse to be swayed by new information.

"This has been an exercise in frustration. It's sort of a David and Goliath situation," said Ellis.

The interchange is part of an $8.2 million project by the Virginia Department of Highways and Transportation to widen the narrow four-lane stretch of Rte. 50 between Edison and Manchester roads later this year. Highway officials consider that section of the road to be one of Arlington's major traffic bottlenecks.

While elimination of the traffic tie-ups is welcomed by members of the Glencarlyn Citizens Association, which represents about 400 households, they are worried about the increase in traffic noise and a possible decrease in their property values.

Ten houses facing Rte. 50 would be 110 feet from a proposed eastbound entrance ramp. When construction is finished next fall, traffic on Rte. 50 will be 140 feet away from the houses. Most of the trees between the houses and Rte. 50 will be removed, although the state changed its plans in order to save some of the trees.

The citizens group has enlisted the support of County Board Chairman John G. Milliken, Del. James F. Almand (D-Arlington) and Rep. Frank R. Wolf (R-Va.), all of whom have written letters to the highway department expressing concern over possible noise increases.

After initial studies of the site, the highway department determined that the noise increase would be insignificant.

State Highway Commissioner Harold C. King, in a letter to Wolf, said that projected noise levels at Rte. 50 and Carlin Springs Road would be "negligible" when compared to both the existing noise levels on that road and the federal government's criteria for mandating noise abatement procedures. King also said that the noise barriers would not be cost effective.

"Even if cost-benefit considerations were favorable, an acoustically effective noise barrier would have to run continuously along Rte. 50 and Carlin Springs Road. Such a barrier cannot be achieved without blocking access to residential and commercial activities along Carlin Springs Road," King said in his letter.

Residents in the area objected to a 1983 noise impact study because a computer model, approved by the Federal Highway Administration, did not require a visit to the site. The first study also failed to include noise generated from cars on Carlin Springs Road and the eastbound entrance ramp onto Rte. 50.

R. Lin Lemon Jr., an engineering design supervisor for Arlington's department of public works who is working with the Glencarlyn residents, said that there were more sophisticated computer models that the state could have used. "The model that the state uses is an accepted model. I think it's more of a textbook-type modeling procedure rather than a field-generated model," said Lemon.

After pressure from the citizens group and their elected officials, an on-site review was done in March by the highway department's environmental quality division. The same conclusion was reached.

"He an engineer went back on a field trip to confirm what we had determined. There was nothing in meeting the requirements of the noise study that needed to be done," said Donald M. Wagner, urban programs engineer for the highway department, who is heading the Rte. 50 project.

Ellis said that residents have not seen any of the results of the subsequent highway department tests.

"We haven't seen any of the documents. They've made a decision without giving us any support. We have never seen any of the hard facts," Ellis said.

In a telephone interview, Wagner said that the engineer who visited the site in March did not produce a written document because nothing differed from the original studies.

"We have exceeded 67 decibels the Federal Highway Administration limit , but that's where we have to make the decision about cost effectiveness," Wagner said. He estimated that a sound barrier would cost $118,000.

Residents say that they would prefer a sound wall, but would be satisfied with an earthen berm as a sound barrier. Wagner said there are no plans to construct a berm between Rte. 50 and the service road because money would be needed to purchase dirt to construct the berm. It also would require removing all the trees in the area.

A berm "would destroy every bit of vegetation in there," said Wagner.

"It seems the traveling public has been accommodated, but in terms of protecting the neighborhood, little or nothing has been done," Ellis said.