The Howard County Council has ended one of the most hotly contested zoning cases in a decade by approving development of a shopping center and up to 600 houses on a 135-acre tract at the traffic-congested intersection of Routes 29 and 103 in Ellicott City.

The project, known as Long Gate, first was proposed in 1977 by developers James and Robert Moxley. But opposition from surrounding residents, who raised concerns about traffic, stymied efforts to rezone the property for the past eight years.

The council, acting as the county Zoning Board, broke the impasse last week by voting 3 to 2 to rezone 10 acres of land for a shopping center. In a separate action, it voted 4 to 1 to rezone 125 acres for town houses and detached homes. The votes came on a compromise proposal mapped out by the council as part of a comprehensive update of the county's master plan.

Reaction was mixed.

"We're discouraged right now," said Janice Bloodworth, a nearby resident who has fought the development since its inception.

"It's been going on so long, I hardly have a reaction," added James Moxley, who heads Security Development Co. Inc., which owns the Normandy Shopping Center on Route 40.

The proposal is a scaled-down version of a rezoning request that the council approved in 1982. That rezoning would have permitted construction of a 150,000-square-foot shopping center and up to 780 residential units, most of which would have been town houses.

A citizens group that has been battling the development challenged the council's action in Howard County Circuit Court. A circuit court judge upheld the rezoning, but the Maryland Court of Special Appeals reversed the decision in 1983 and ordered further hearings.

In the latest round of debate, county planners recommended approving the 1982 rezoning without changes, but more than 1,300 residents from four surrounding communities signed petitions opposing the request.

To answer citizen concerns, the council drew up the compromise, which cut the number of housing units by 30 percent and reduced the size of the shopping center by half.

In all, developers now are limited to building 182 town houses, 413 single-family homes and a 60,000-square-foot shopping center, said County Zoning Administrator Grace Kubofcik.

Traffic congestion was a key issue in the debate. Route 29, also known as Columbia Pike, is a major county thoroughfare that connects I-70 in northern Howard County to the Beltway in Montgomery County. In between, the road is straddled by the new town of Columbia.

The road intersects Route 103 and branches into Old Columbia Pike, a main road into Ellicott City, at the same location. The confusing interchange causes bumper-to-bumper traffic during rush hours and often causes delays of up to four traffic light cycles, Kubofcik said. Citizens argued that the development -- and particularly the shopping center -- would make an already bad traffic situation much worse.

Although the state of Maryland is planning to spend up to $12 million to rebuild the interchange, construction is not slated to begin for at least two years and possibly longer, according to local officials.

Citizens also said the area is now served by four shopping centers on Route 40, two miles to the north, and also would be served by a proposed shopping center at the corner of Routes 108 and 29, about a mile and a half to the south.

"Traffic is extremely bad . . . and hundreds of citizens say they don't need a shopping center there. I thought it was premature at best," said council member Lloyd Knowles, who opposed the rezoning.

James R. Schulte, a Security Development vice president, said his company offered to pay for interim improvements to the intersection to handle any additional traffic.

"Our traffic studies show that the intersection could be made to operate up through the Long Gate project . . . but the state told us not to waste our money," he said.

Under the current plan, Schulte said that the 10-acre site designated by the council for commercial uses is inadequate for a neighborhood shopping center.

Developers had hoped to anchor the center with a grocery market and a drug store, but a grocery market alone would require at least 40,000 square feet of space, which leaves only 20,000 square feet for other stores, he said.

"We, quite frankly, don't have a grip on that right now," Schulte said. "We're going to have to go back to the drawing board on that one."

Meanwhile, opponents say they probably will not go to court to challenge the rezoning again.

"I don't see any legal recourse other than challenging the whole comprehensive rezoning process, which I think would be impossible for a small group of citizens," Bloodworth said.