District officials have drawn up a revised, $90 million plan to build a long-debated bridge across the Anacostia River and a highway through a stretch of national parkland on the river's west bank.

The proposed bridge would connect the heavily used Southeast Freeway with the Anacostia Freeway, and the planned highway would link the Southeast Freeway with the East Capitol Street Bridge.

After protracted negotiations with federal and other officials, the city has adopted key changes to its initial proposals in an attempt to clear environmental obstacles and objections by critics concerned about the encroachment of rush-hour traffic on federal parkland.

The changes include narrowing the proposed highway from four to two lanes and sharply reducing the height of the new bridge to make it appear less obtrusive. Despite the moves, the revised plan is likely to be assailed by environmental activists and other opponents at a final hearing, probably in September.

The two-pronged project is expected to comprise the city's last link to the federally financed interstate highway network. The project was designed to provide a more direct route to the downtown area for thousands of commuters and to ease traffic congestion in Capitol Hill, Anacostia and other residential areas.

"The traffic benefits are real on both sides of the Anacostia River," said Gary A. Burch, chief of design and engineering for the D.C. Department of Public Works, who is overseeing the project. The city's main goal, Burch said, is to divert traffic from residential neighborhoods to freeways.

Nevertheless, an antifreeway campaign has been mounted by a group called the Citizens' Committee to Stop It Again, a name meant to recall highway protests of earlier decades. The group has labeled the new plan an attempt to revive the "east leg" of a long-defunct proposal for an inner loop, or downtown beltway.

The proposed bridge and highway, which are scheduled to open in late 1989 or early 1990, are expected to be used by 77,000 cars and trucks a day on weekdays.

City and federal officials plan to reach a final agreement on the long-delayed project after the public hearing and to begin construction by early 1987.

The city's contention that the plan will relieve traffic congestion has been disputed by some opponents. They have argued that rush-hour traffic will remain "unchanged" on local streets and that the proposed bridge and highway will lead to increased traffic in nearby communities at other times.

"We don't see why we have to sacrifice our neighborhood for the convenience of people who should be taking the Green Line when the Metro subway system is completed," said Janet Searcy, a leader of the Citizens' Committee to Stop It Again, which has collected 1,400 signatures on antifreeway petitions. The Green Line is expected to open in 1990.

The city's plans are also opposed by environmental groups, including the Sierra Club, and by the board of directors of Congressional Cemetery, a historic burial ground founded in 1807.

The cemetery is at 18th and E streets SE, near where the highway and bridge are planned.

"Our concern has been to protect the vista," said Christopher C. Herman, a cemetery board member, citing objections to the proposed bridge.

"With the rumble and the roar, it would just attract attention to itself," he said.

Nevertheless, the city's proposals appear to have gained at least tentative backing from key federal agencies, including the Federal Highway Administration, Coast Guard and National Park Service.

Advisory neighborhood commissions and civic groups in Capitol Hill and the Anacostia area also have endorsed the plan.

"There is a real groundswell in the community to do something about the traffic," said Pat Schauer, a board member of the Capitol Hill Restoration Society.

Under the city's plan, the Southeast Freeway would be linked to the new bridge and highway just west of the Anacostia River, at Barney Circle.

The new highway, or boulevard, would run along the western side of the river for about a mile, to the East Capitol Street Bridge.

The new bridge would link the east and west banks of the Anacostia River and parallel an existing Conrail bridge.

The new bridge would extend northeast to the Anacostia Freeway and Kenilworth Avenue.

The project is designed to close what traffic engineers have long viewed as several troublesome gaps in the city's highway network.

Because of these missing links, many drivers now cannot travel between the downtown area and the city's northern and eastern outskirts without a detour on residential streets.

Traffic on the Southeast Freeway cannot reach the East Capitol Street Bridge without traversing local streets.

Inbound commuters heading south on the Anacostia Freeway cannot enter the 11th Street or Pennsylvania Avenue (Sousa) bridges without detouring through neighborhood streets.

Nor can outbound drivers get on the northbound Anacostia Freeway without a detour.

Because of a 1978 congressional measure, the project is expected to be the District's last interstate highway segment.

The federal law barred interstates for which environmental impact statements were not prepared by 1983.

Only one other interstate project is scheduled to be built in the Washington area -- a road in Montgomery County called I-370, near the Shady Grove Metro station.

In the revised plan, city officials have lowered the proposed bridge from 28 feet to 14 feet above the river's level at high tide.

The shift was triggered by complaints that the 1.5-mile, four-lane structure would be an eyesore from the vantage point of Congressional Cemetery and nearby areas.

The Coast Guard has not announced whether it will grant a permit for the bridge, but a Coast Guard official said the proposal appears "acceptable to navigational interests."

To further lessen the impact of the proposed highway on parkland, city officials have designed a curving alignment set as far from the river as possible to deter speeding and to have the road blend with the landscape.

They have recommended enclosing the western end of the highway in a short tunnel -- a step that would make it possible to reduce the height of the new bridge further.

A National Park Service spokesman described the proposed revisions as "acceptable in concept" and said he foresaw no major obstacle to the city's plans.

The Park Service is drawing up plans for park improvements on boths sides of the river as an adjunct to the city's project.

These plans are expected to include bicycle paths, scenic overlooks and playing fields on the river's currently undeveloped west bank, not far from D.C. General Hospital and Robert F. Kennedy Stadium. On the east bank, walkways would be built over the Anacostia Freeway and an existing roadway may be set back to provide more open space along the shore.