Nearly a hundred residents packed into the Hardy Recreation Center in Northwest last week to protest a plan by Georgetown University to install a traffic light at the campus' south entrance on Canal Road NW, a short distance west of Key Bridge.

The university proposes to make its south entrance the main entrance to the campus to alleviate traffic congestion on the narrow streets of Georgetown. Its plans call for a left-turn lane eastbound on Canal Road to permit access across the westbound lanes of Canal Road into the university. The light would not permit cars to turn left from the university across the eastbound rush-hour traffic in the morning, but would allow cars to turn out of the university onto Canal Road toward Key Bridge in the evening.

At the hearing, conducted by the city's Department of Transportation, residents of the Palisades and Foxhall neighborhoods west of the university said the traffic light would mean more tie-ups, more cars blocking their streets, and more cars speeding down narrow streets, imperiling children walking to four neighborhood schools. Speaker after speaker predicted that the left-turn lane would fill up during morning rush hour, causing more traffic jams on Canal Road.

"We just can't believe that they would attempt to take Canal Road, which is already bumper-to-bumper, and impede the flow of traffic further," said Robert Siciliano, president of the Foxhall Community Citizens Association.

The university's traffic consultant, Stephen G. Petersen, said the light and the left-turn lane would not impede morning rush-hour traffic because it would prohibit left turns out of the university into the eastbound stream of traffic during the morning rush except for 20 seconds every hour when the student-run bus service vehicles would depart.

Because only a small percentage of the traffic coming into the university approaches from Canal Road, the left-turn lane would not fill up and spill into the traffic lanes, Petersen said.

Although cars from the university would be permitted to cross the westbound lanes of evening rush-hour traffic, Petersen predicted that the traffic situation would improve because currently, those cars leave the campus on 34th Street and contribute to backups at the foot of Key Bridge. That tie-up would be alleviated slightly if campus traffic could turn directly off Canal Road onto Key Bridge, he said.

The university received a $600,000 grant from the Urban Mass Transit Administration to modify the south entrance, which leads to the university parking lot. The money would be used to install the traffic light, construct the left-turn lane and cut through the median strip on Canal Road to the proposed new main entrance. Currently there are two main entrances, one at 37th and O streets NW and another at 37th and Prospect streets NW, as well as five other entrances along Reservoir Road NW. Once the south entrance is modified, the 37th and O streets entrance would be closed.

If the city's transportation department approves the university's plan for the traffic light, it will mean that the city will allow the university to tear up part of a new median strip and sidewalks project that involved resurfacing Canal Road from Key Bridge to the Foxhall Road-MacArthur Boulevard intersection. The city applied for federal money for the project in 1979, city transportation officials said, but the project wasn't approved until last year.

Dean Price, the university's architect and director of facilities planning, said the south entrance is needed to manage traffic on main arteries rather than residential streets. He said the proposal was submitted to the city's Board of Zoning Adjustment in 1977, as well as to area advisory neighborhood commissions. Both groups approved the plans, Price said.

"We're more than surprised with [the response of] the Palisades people," said Price, referring to complaints by residents of the Palisades community near Georgetown. "Only 14 percent of our traffic comes from that direction at all. Forty-seven percent comes from Virginia and that's why we want the left turn. We did that specifically to aid the community around us."

Leaders of some community groups have complained about what they said was lack of information about the proposal, however, and how it would affect their neighborhoods. They also wanted the university to discontinue its plans until a study is completed that might call for changes to the Whitehurst Freeway and its access to Canal Road.

Speakers at last week's hearing expressed incredulity at the results of the university's traffic studies.

"These studies that I have heard sound like they're out of touch with reality," said Katherine Hueper, a resident of Foxhall Village. "When I heard of this project, I shook my head in disbelief. These elaborate studies all sound very well, but we don't need a study to show that three major arteries -- Canal Road, MacArthur Boulevard and Foxhall Road -- cannot funnel into two lanes without creating a horrendous traffic jam. You cannot put a light there without making things worse. It's mind-boggling."

Petersen said that the citizens of the area are partly responsible for the traffic now flooding their neighborhoods, because in the early 1970s, they steadfastly opposed construction of the I-266 freeway that would have connected with the the proposed Three Sisters Bridge across the Potomac and along Canal Road.

"Maybe they were right in opposing the freeways, but now, 10 years later, they are seeing what happens when there isn't any backup plan," Petersen said.

Influential residents of Georgetown and surrounding neighborhoods also opposed a plan to have a Metro subway stop in Georgetown as well because they feared it would increase the number of people coming to their neighborhoods and would damage the foundations of many historic homes. A decade later, Georgetown automobile and pedestrian traffic is more congested than ever.

The Department of Transportation will not make a decision on the proposed traffic light for at least three months, a spokesman said. Interested parties have until Oct. 31 to submit comments on the plan. If the department decides to install the traffic light after conducting its own studies, a notice will be published in the D.C Register.

Siciliano, the president of the Foxhall Community Citizens Association, said his members will continue to petition DOT not to install the traffic light.