Myra Smith, a visitor from Cincinnati, alternately creeped and braked along Wisconsin Avenue in Bethesda in her rented Ford. She looked at the fretful faces in the other District-bound cars, gazed up at the stylish new towers on each side of the street, and watched as the traffic light far ahead changed from red to green to yellow to red again.

"Good grief," said Smith, a 35-year-old social worker, during a typically challenging morning rush hour last week. "Maybe I should just abandon the car and walk."

Traffic spells trouble in Bethesda, the former bedroom community and center of small-town shopping that has exploded into a congested mini-city during the past decade. The problems are so serious that the Montgomery County Council last week put the brakes on most new commercial development in the central business district while county officials seek solutions.

The decision comes at a time when Bethesda, the strategic gateway between the District of Columbia and the rest of Montgomery County, is struggling to reconcile its identity as "a prestige location" for development with the need to remain an attractive place of suburban residences and neighborhood stores.

That such a predicament could occur despite deliberate calculations of county officials illustrates the uncertainties inherent in development planning. A combination of factors apparently contributed to the situation -- an overestimate of the number of people who would use public transportation and ride-sharing programs, exaggerated estimates of the number of cars that could be accommodated on Bethesda's major roads and, according to some critics, the county's eagerness to attract new development at the expense of residents and small businesses already in place.

"I'm not one of those nostalgic people," said Helen Blunt of the Edgemoor Civic Association, whose home of 30 years borders on the business district. "I don't believe in hitching posts. But Bethesda has lost the flavor of being a town, even though the intention of the planning board was to make it a town."

In the past five years, the county has approved 13 major commercial development projects in Bethesda involving 17 buildings, said county planning department spokesman Don Downing; all but three of these projects have been completed or are under construction. Charles Stuart, president of the Bethesda-Chevy Chase Chamber of Commerce, estimates the value of that new construction at a minimum of $200 million.

As a result, Bethesda's main business district, concentrated along Wisconsin Avenue, resembles a compact but stylish urban center in the making -- 15 blocks long and six blocks wide. The Bank of Bethesda and the Hot Shoppe still sit at the intersection of Wisconsin and East-West Highway, but they are overshadowed by buff- and salmon-colored high-rises with brick courtyards and modern sculptures.

The obvious center of activity is the Bethesda Metrorail station, which opened in December 1984. Nearby, a big orange banner announces that a Burger King is opening soon, and flags wave from the new Hyatt Regency Hotel. Up and down Wisconsin, the traffic problems are exacerbated by the clutter of utility trucks, concrete mixers and cranes spawned by the construction; often, at least one lane is blocked.

The projects were all developed under the county's master plan, which was devised in 1976 and amended in 1982. In fact, the 1976 plan set more stringent limits on building in Bethesda than had originally been permitted. "It could have been a whole lot worse," said Peter Meleney, chairman of the Bethesda Coalition, a group of civic associations that surround the central business district. "We could have had lots of 18-story buildings by now."

Approval of the various projects was based on traffic calculations involving the number of rush-hour "trips" the proposed project would generate into and out of Bethesda on the major roadways. In 1982, the county planning board set a ceiling of 1,675 trips per rush hour for the high-rise projects, and it stopped approving those hotels and office towers when that limit was reached.

Also at that time, planners predicted that moderate-scale development surrounding the high-rise heart of the business district would generate another 200 trips per rush hour. But a boom in these medium-sized projects quickly exceeded that limit.

The council's vote last Tuesday to halt the moderate-scale development was prompted by a study showing that traffic congestion is rapidly approaching the calculated limit of 15,408 vehicles an hour on the major roads in Bethesda's central business district. The limit, said Henry Bain, the County Council's legislative analyst, is "a certain standard of congestion regarded as tolerable."

"There is no magic ultimate disaster or gridlock," he said. "It's simply that the more cars you have, the more long queues you have, the more time it takes to get through those queues and the more interference there is with other intersections."

That Bethesda would eventually become a hotbed of development was virtually ordained by its location on the District border. In the 19th century, its character was formed as affluent Washington residents migrated north and west to escape the city's swamplike heat.

In 1904, the opening of the trolley lines to Washington signaled the beginnings of the community's development. With the area population explosion after World War II, Bethesda and much of the rest of Montgomery County blossomed.

These days, while Bethesda is not -- and may never be -- an incorporated city, its population is estimated to be more than 60,000. Added to the comings and goings of those residents is the traffic that uses Wisconsin Avenue, also known as Rte. 355, as a major north-south artery between the District and the rest of Montgomery County.

"I haven't driven Wisconsin in six years," said resident Blunt. "I avoid it at all costs."

The first in a series of steps to help lighten the congestion will take effect Aug. 3 with a rerouting of some Bethesda traffic. The plan will make part of East-West Highway and Old Georgetown Road a one-way westbound route. Old Georgetown Road's eastbound traffic will be rerouted via Woodmont Avenue and Montgomery Avenue.

Other remedies include synchronizing traffic lights on the major roadways, the completion of an underpass at the Wisconsin Metro Center that would reduce pedestrian traffic, the construction of a five-story garage to provide much-needed short-term parking, and an extension of Woodmont Avenue as a parallel route to Wisconsin.

There are a lot of things in the works," said Gail Nachman, director of the Bethesda-Chevy Chase government center, a liaison between civic groups and the county government. "The problem is, we are going to have to live with the situation for a while. Unfortunately, residents want to be able to use Bethesda for hardware stores and cleaners, but they can't get to them."

Another concern of the Bethesda-Chevy Chase Chamber of Commerce is the effect of the no-growth period on the overall makeup of the business district.

"We think certain limited retail should be allowed to go forth," Stuart said. "We need more restaurants and we need more small stores. We don't want Bethesda to become an office canyon."

But despite the uncertainties, Stuart, Meleney and others say they are optimistic about Bethesda's future. After all, they point out, Lowen's Toy Store has come back.

Lowen's, a Bethesda fixture since 1960, was displaced along with many other small businesses by the wave of development and renovation along Wisconsin Avenue in 1984. Three weeks ago, Lowen's returned to its former spot, where the sleek Bethesda Gateway building now looms.

"We're the first and, I think, the only small business to be forced out and to have the financial ability or the popularity to come back in," said owner Scott Goode. "We think of it as a homecoming."