Allen Bender has a disturbing vision of the future of his community. When he looks at the vintage 1950, brick houses in Randolph Hills, just east of Rockville Pike, he foresees a slum.

"It's a classic kind of thing," said Bender after a meeting this week of the Montgomery County Civic Federation. "There are fortunes to be made. Speculation will force up property. People will be forced out, and there will be no one left to fight.

"The area will be zoned commercial," he predicted, "and my neighborhood will become a slum."

Bender, 50, an independent hospital consultant, was predicting the impact of the $214-million complex proposed for the White Flint Metro station just northwest of his community. The proposal is one of four residential-commercial-retail projects designed around Montgomery County Metro stations that are scheduled to be opened in 1983.

These plans worry many civic leaders, and about 20 of them brought their concerns to the civic federation meeting at the County Office Building. Their central question was whether the subway system's extension to Shady Grove will create new urban centers around the stations, with city problems such as crime and pollution.

"I went to the movies a few weeks ago in Silver Spring, and I was scared to death to walk three blocks to my car," said A. Chester Flather Jr., moderator of the session. "It's crime-infested, and I blame a lot of this on Metro."

Despite their protests, Bender and Flather acknowledge they are too late to effect any major changes in the Metro developments, all of which come under a master plan approved by the County Council in 1978. According to county planners, the projects at White Flint, Bethesda and Friendship Heights comply with the sector plans established and approved three years ago. Rockville's development has yet to be proposed, but planners say the city is backing a huge project.

"We should have gone to court back then (in 1978)," said Flather.

The master plan is to serve as a guide for the size, scope and environmental impact of the three developments at various stages in the county's review process. Rockville will use an independent planning-approval process.

The projects proposed for White Flint and Friendship Heights have been approved by the Montgomery County Planning Board, according to John Westbrook, chief of the Urban Design Division, Maryland-National Capital Park and Planning Commission. The Bethesda and Rockville proposals are still on the drawing boards.

White Flint's development plan is the most ambitious. On 33 acres east of Rockville Pike and south of Old Georgetown Road, Metro proposes a complex of shopping malls, a hotel a 765 residential units. This core development would mesh with others south of Marinelli Road and west of Rockville Pike, according to county planners.

At the meeting this week, Westbrook described the Friendship Heights project as "the grand foyer of Montgomery County." The complex of office buildings, retail and commercial space, linked by a partially enclosed pavillion and outdoor plaza, adds up to 237,000 square feet, he said, and will cost more than $20 million.

Norman Knop, representing the Citizens Coordinating Committee on Friendship Heights, asked whether planners are". . . using the Metro as a tool to urbanize the county? Are we moving employment centers out to the suburbs away from the established urban centers?

"Many people feel metro is being used as a development tool and transportation is taking a secondary role," he said. "I think everyone agrees that there should be development disagreement as to what form."

Although the site in Knopf's neighborhood is ready for the bulldozer, the projects planned for downtown Bethesda and Rockville have yet to be approved by respective county and city planning boards. But planners predict smooth sailing for both.

An application from local developer Rozansky and Kay Construction Co. for the Bethesda complex is due any day, according to county planner Jake Pierce. The firm is proposing Avenue next to the post office, a 15-story office building on Woodmont Avenue and a three-story commercial building on a central plaza -- a total of 640,000 square feet, according to Pierce.

At the intersection of Old Georgetown Road, East-West Highway and Wisconsin Avenue, Clarke Enterprises has a permit to construct an 18-story office building with two floors of commercial space. Bethesda is negotiating with prospective builders for a 50,000-square-foot site just south of the Metro station, Pierce said.

Rockville is seeking a developer for an 800,000-square-foot complex around its downtown Metro station. The city recently approved a report recommending a development of that dimension, according to Planning Director James Michael Davis.

County Planner Westbrook noted, after this week's meeting, that the 1978 master plan was approved after four years of meeting and studies.

"There was a tremendous amount of community participation," he said. "Not everyone was pleased. The developers wanted more space and some citizens wanted more restrictions.

"But it was a compromise."