Nearly 200 people who crowded into a Manassas meeting room this week were defeated in their last-ditch effort to block construction of a shopping center in rural Prince William County.

After a three-year debate that resulted in scaling down of the developers' original plans, the county board of supervisors approved rezoning that will allow work to start on a neighborhood shopping area at the southwest corner of Rte. 234 and Counselor Road.

Residents of the area, who said they moved to Prince William to get away from the crowds and congestion in other parts of the Washington area, left the meeting angrily charging the supervisors had ignored the citizens' wishes. "I'll never spend a dime in that shopping center," said one man.

In an attempt to overcome the community opposition, local developers Lloyd R. Crowne, Robert M. Caton and Paul B. Ebert cut back the proposed size of the shopping center from 12.2 acres to 10 acres, agreed to put a 100-foot buffer between the center and the surrounding area along Counselor Road instead of the 30 feet originally proposed, said they will restrict development on 29 acres they own in the surrounding area to single-family homes on lots no smaller than one acre, and dedicated to the county 1.7 acres of land on the east side of Rte. 234 for "library use or other purposes."

The approved plan calls for 80,000 square feet of shopping facilities, with a promise not to build gas stations or fast-food restaurants. The developers' first proposal provided for 75,000 square feet of development. The first plan also contained the landowners' agreement to pay for connections to public water and sewer facilities, as well as to widen Rte. 234 to provide left-turn lanes into the center and to dedicate right-of-way for the "ultimate upgrading" of the road.

The developers' concessions failed to mollify the area's residents. Members of the Woodbine Woods community association voted against the revised proposal by a five-to-one margin, the organization's president, Ray Dominguez, told the county board. Residents of the approximately 270 homes in Woodbine Woods and other nearby communities believe the shopping center will change the rural character of the area and create traffic hazards. Rte. 234 is a "substandard road that is dangerous" and carries "more traffic now than it can handle."

Prince William residents defeated a $20 million road bond in last month's election, "sending a signal" to the county government that citizens want to slow down development, said some at the meeting. The money would have been used to upgrade several of the county's most overburdened roads, planning director Roger W. Snyder said in an interview. "We are millions of dollars behind in road improvements," he said.

Dominguez said citizens fear the shopping center will "attract loiterers" and other unsavory characters, and in general create conditions "inconsistent with the health, safety and welfare" of the surrounding communities. He also asked whether "this will be the first in a long string of dominoes" of strip commercial development.

He and others speaking at the meaning gave the supervisors several petitions opposing the shopping center.

The county supervisors approved B-2 zoning, which allows less intense, neighborhood-type commercial development than the B-1 zoning the developers requested. The B-1 is an all-purpose zoning category that places few restrictions on development, allowing shopping areas the size of Tysons Corner and Fair Oaks Mall. Before the vote, the area was zoned for agricultural use.

Board Chairman K. K. Seefeldt said she did not "like to vote in opposition when there has been such well articulated" citizen concern. She said, however, "I don't think we can defend denial of zoning in court."

Citing a reason for her support of commercial development, Seefeldt said "residential development is a negative on the county from the point of view of the tax base." Supervisor J. D. Jenkins agreed, saying "It costs us $400 per residence to subsidize residential development. It doesn't cost us that for commercial."

The shopping center approved this week will be the first commercial development in the area, where most residents live on large lots of an acre or more and must travel to Manassas or Dale City for shopping. Prince William's 1982 comprehensive plan, however, designates an area 200 feet south of the shopping center cite as "neighborhood commercial," for providing services such as food and drug stores, dry cleaning, laundry, shoe repair, and medical offices, according to a county staff report. "It would be reasonable to include the subject site in this neighborhood commercial area," the report said.