Municipal planners from the Gaithersburg area met with Montgomery County planners this week, voicing their concerns about the consequenses of zoning changes that are proposed in a new vicinity master plan.

Although both local and county officials said that the meeting--which was the first joint conference for Rockville, Gaithersburg and county planning board members--helped create a mutual understanding of traffic problems, sprawling development and economic competition, the essential conflicts remained unresolved.

"I felt they listened to us, and we heard what they had to say," said Jeffrey L. Rubin, chairman of Gaithersburg's Planning Commission. "The question is, what will happen now that we understand each other?"

At issue is the first comprehensive rezoning since 1971 of the land surrounding Gaithersburg and the road systems and other public services that tie it all together.

Officials gathered in Washington Grove and circled themselves with easels bearing "master plans," "generalized plans," "tax maps" and "corridor cities" diagrams, each a colored patchwork stitched together like a Frankenstein's monster, representing two-dimensional attempts at bringing competing land uses into a harmonious whole.

While the agenda set by the county planning board members attempted to break the discussion into categories, it wandered nevertheless into a milieu of components, and then back to the beginning.

"All of this is like a web," James Davis, Rockville's planning director, said. "You start talking about traffic, then all of a sudden you find yourself talking about density, agricultural preservation. . . . You untangle one part of the web, and it can hurt the fabric of the whole thing."

County Planning Board Chairman Norman L. Christeller said his board is trying to promote a new concept that will stake out an orderly and equitable scheme for development in the Gaithersburg area.

But city planners and council members said at the meeting that they have invested the past decade in preparing their commercial districts for development along the lines of the old plan. Now that the proposed master plan would allow some of the same commercial and industrial development in the Shady Grove area between the two cities, municipal officials fear they will have to compete with the county to attract business. The Shady Grove area, with its proposed similar densities and building heights, could become a "third city" officials said.

The "corridor cities" of the old master plan have metamorphosed into a "corridor spine" of development along I-270 that would grow less dense as it receded from the highway.

City officials also complained that county planners continued to allow more subdivisions to be built, whose residents would use already overloaded roads, especially Rte. 28.

"What we can permit is limited by how fast the road system develops," Christeller said.

"Or by how much pain we can tolerate," Rubin replied.

Gaithersburg and Rockville officials also objected to proposals in the master plan that would cut back the cities' expansion limits from their current parameters.

Leah Barnett, a member of Rockville's planning commission, questioned whether too much of the county's "moderate priced" housing was placed in Gaithersburg and Rockville.