The Century Freeway, which is supposed to be one of the last major urban expressways built under the federal interstate highway program, has turned into a sick joke about bureaucracy in action.

It has been eight years since a coalition of freeway-fighting environmentalists brought the Century project "temporarily" to a halt. The fruits of that legal effort include:

A 17.2-mile swath of unrelieved blight south of Watts and Compton and other black and Hispanic areas. More than three-fifths of buildings in the right way had been removed when the environmentalists won an injunction against the freeway in 1972 and almost nothing but crime has happened in the right of way since.

An ambitious replacement housing program that has become ensnarled in procedure and, 14 months after agreement was reached, has yet to replace one house.

An angry highway lobby, some of whose members are suing to block what they see as an effort to spend road money illegally for housing.

Norm Emerson was in charge of the project for the federal government until recently, and in a masterful display of understated bureaucratese, he calls the Century Freeway "a clear example of governmental inability to come to grips with a complex problem in a changing environment."

As a result of a complicated court agreement struck in October 1979, the Century is now supposed to be back on track. When it is completed, some time around 1990, it will have all of the mind-boggling numbers that accompany urban freeways.

More than 25,500 people will have been forced from their homes (almost 18,000 already have been). It will be 10 lanes wide, with two lines devoted exclusively to express buses and carpools and convertible to a commuter railroad track bed. Some of the interchanges will be 10 stories high.

The cost, including the housing program and right-of-way acquisition, is officially estimated at $1.5 billion, more than $87 million per mile. Some officials familiar with the project think it will cost at least $2 billion, maybe more. By one estimate, every month of delay now adds $7 million to the cost of completing the Century.

The issue that has the nation's highway lobby in a dither is not the cost but the housing replacement program. It has been accepted (and required by various federal laws since the 1960s) that highway builders must fairly compensate citizens for property they take and help find new homes for those they displace, but the court decree that revived the Century project requires more.

It requires that 4,200 housing units, most of them for low and moderate income families, be constructed or rehabilitated within six miles of the freeway. Most of the money for that construction and rehabilitation will come from the federal highway trust fund, that once-great engine for highway construction that has fallen on hard times. With gasoline consumption down and construction costs up, the 4-cent-a-gallon tax that is the primary source of funding for the trust fund has proven inadequate to the nation's road-building needs.

If the Century decision becomes a precedent requiring road builders to replace housing in addition to compensating people who lose their homes, then the highway trust fund will have a greater burden to bear at a time that it is already spending more money that it is taking in.

Darrell Manning, director of the Idaho Transportation Department and an activists in national highway affairs, puts it bluntly. "It is almost unconscionable to use highway funds for that purpose when many more times those funds are available for social needs," he said.

Associated General Contractors, a group representing big companies that build highways, has sought in court to block the housing plan because of its dependence on highway money that could obviously be spent with members of the Associated General Contractors.

There is another view, the one the court adopted. Ray Kassell, director of the Iowa Department of Transportation and a man who is regarded as progressive on the subject of highways, puts it this way: "When you disrupt people for the good of total society, they should be made as well as they were before the action took place . . . When you build something like the Century Freeway, you have to recognize how broad that impact is. So [that housing program] will just have to part of the total cost."

Rudy Subia, Century project manager for the Federal Highway Administration, granted that "there is no precedent" for the housing program. The concept, he said, is to "restore to the community a resource that it had -- low-cost housing . . . I can't afford housing down here; you really have to wonder what poor people can do."

The Century Freeway is the last uncompleted link in the planned Los Angeles Basin system that is either one of the world's wonders or world's horrors. It is officially known as the El Segundo to Norwalk freeway, but was dubbed the Century, probably (but not absolutely) because it will parallel the 100th block south from center Los Angeles. The Century will run east-west and provide a badly needed high-speed connection to Los Angeles International Airport.

It is supposed to take an enormous amount of truck and automobile traffic off overburdened neighborhood streets, particularly Imperial Highway, provide construction jobs and attract industry and shopping, especially near the interchanges. Estimated daily traffic on the Century will be 160,000 vehicles (the busiest section of the Washington Beltway carries about 120,000 vehicles per day).

If the environmentalists had not sued, the Century would have been completed by now. But there would not have been a housing replacement program or exclusive bus lanes in the right of way or a strong requirement for minority participation in the construction program.

The Rev. David Andrew Scott, a black pastor and member of the Housing Advisory Committee that monitors the Century project, said that right-of-way acquisition "disrupted one of the nicest communities in the south-central area, [but] I think the attitude now is let's get on with it. Demolitions have taken place, houses are boarded, families have moved. People wonder why we're not getting on with it."

One of the reasons they're not getting on with it is that it takes time to restart a project that was abandoned for eight years. The designers and engineers are busy with their drawings and schedules. The housing people began surveying possible sites either to build new housing or to rehabilitate structures.

There has been substantial criticism that it is taking too long, and that criticism is combined with another factor: black activist Ted Watkins has proposed that a large abandoned industrial site be turned into a huge housing project.

Watkins has a record of getting things done and is an ally of Mayor Tom Bradley. Thus, he has been able to maintain pressure for consideration of his proposal despite the clear preference of both California and federal officials at the working level to disperse housing throughout the Century corridor rather than concentrate it in one big project.

William A. Kellar, chief of the Century project for the state department of housing and community development, said he has felt pressure both to accommodate Watkins and to speed up the housing program. "It should have been more important to do it right than to do it quick," Kellar said.

He mentioned several times the need to establish and follow "a process" and said once a process is in place, he will have no trouble meeting the court-imposed quotas. Under the settlement, 30 percent of the housing units must be available by the time half the highway contracts are awarded. "The court decree gave me until May 1984 to have 1,200 housing units available . . . " he said.

The first housing project, a small one, will probably be advertised for bids next month.

Ten years for a major urban highway project is not that long, if one considers the amount of time that is spent in planning and designing. But once people are being moved and their homes razed, it seems interminable, Federal Highway Administrator John Hassel said.

"Some people may feel they have won if they delay, but the neighborhoods and the community lose, he said. "It will take another 6 to 10 years and in the meantime we'll still be doing some very negative things to a lot of people.

"Anyone who has seen that corridor would say, 'Yes, we have damaged those people.' If we had done that in our private lives, we could be sued for damages."