Area officials and organizers of Saturday's 20th anniversary March on Washington said yesterday they expect--and will be able to accommodate--an even larger crowd than the 250,000 who attended the historic 1963 civil rights gathering.

"We're ready for the march," one city official said at a news conference called to announce final logistical arrangements for the daylong rally and march on behalf of "Jobs, Peace and Freedom."

D.C. Police Chief Maurice T. Turner Jr. said he thought 250,000 would be the "minimum" crowd size. He said his department was specifically concentrating on crowd management and movement of traffic for the event, but noted that special anticrime units would be patrolling other parts of the city.

About 3,600 D.C. police are expected to be on hand for the event, as well as 300 U.S. Park Police officers.

The march from the Washington Monument area to the Lincoln Memorial is scheduled to start at 10:30 a.m., with a premarch rally planned for 9 a.m. in the Monument area and the formal program set to get under way at 1 p.m. at the Memorial grounds.

Black leaders in town for the march said yesterday they want the commemorative event to pump new spirit into American politics and the civil rights movement. They said much has been accomplished since the 1963 march immortalized by Dr. Martin Luther King Jr.'s "I Have a Dream" speech, but that much more needs to be done.

"We must have an economic revival . . . we must have a political revival," said Dr. Joseph Lowery, president of the Southern Christian Leadership Conference, which was founded by King in 1957.

In announcing a final speakers list yesterday, march coordinator Donna Brazile said morning guests would be limited to three-minute speeches while afternoon speakers would have five minutes. Joking that some of those scheduled to appear "have been writing their speeches for two years," she said a warning light will flash at the lectern when speakers have only one minute left and that the microphone "will start to fade" after the five-minute time limit.

The final list of program participants was revised yesterday to include a representative of the homosexual rights movement after gay groups complained they had been intentionally excluded from the program.

March participants will be arriving aboard "Freedom Trains," some 4,200 chartered buses and numerous chartered planes. Others will be coming by private cars, vans, bicycles and even by foot, march organizers said, including an estimated 25,000 people who will walk or take the subway to the Mall as part of nearly 30 separate "feeder" marches that will wind through the city Saturday morning.

Thousands of persons are expected to arrive on their own, without being part of any organized group.

In anticipation of the expected crush of traffic and people, organizers spent the bulk of their time yesterday discussing transportation and parking arrangements for the march.

Beginning at 8 a.m., no traffic will be allowed on Constitution Avenue between Sixth and 23rd streets NW, and only Third and 23rd streets will be open for north-south traffic, organizers said.

Since the Metro system will be used heavily by out-of-town marchers to get to the Mall, Metro officials are advising area residents who take the subway to get off at stations other than the Smithsonian stop. Organizers said they expected most chartered buses would be arriving at Metro's RFK Stadium and Pentagon stations and at West Potomac Park during three peak periods, 7:30 a.m., 9:30 a.m. and 11:30 a.m.

Metro trains and buses will operate on an extended 6 a.m.-to-midnight schedule. The buses will run according to a regular Saturday schedule, but the fleet will be augmented with the addition of 150 buses. The Metrorail fare will be 50 cents, and barrels will be used for collections.

Vans and cars coming into the District should park at satellite areas such as the Cheverly, New Carrollton and Silver Spring Metro stops and passengers should take the subway into the city, march planners advised. Parking at all of Metro's fringe sites will be free.

Three "Freedom Trains" from Miami, Boston and New Orleans will be arriving at Union Station at 6:05 a.m., 7:47 a.m. and 8:55 a.m., respectively.

The Mayor's Committee for Handicapped and Elderly has made special arrangements to help marchers requiring assistance to attend the event. Transportation to the Mall for the handicapped will be provided from RFK Stadium and 605 G St. NW. Those who want to march will meet at 14th Street and Madison Drive, where there will be special marshals in white T-shirts with red lettering to help them as well as toilet facilities with ramps, a first-aid station and interpreters for the deaf. Space for those not participating in the march has been reserved at the Memorial grounds.

Water fountains on the Mall grounds will be identified by helium balloons, and about 600 comfort stations will be set up on the vacant drive along the Reflecting Pool and at other positions on the Mall.

March organizers said yesterday the event is expected to cost about $500,000, of which about 75 percent has been raised. Contributions are still coming in, they said, and organizers also hope to make up the balance through collections and sales at the march. CAPTION: Picutre 1, Martin Luther King. Maps 1 and 2, 20TH ANNIVERSARY MARCH ON WASHINGTON. By Dave Cook--The Washington Post; Pictures 2 through 4, ANDREW YOUNG; CORETTA SCOTT KING; WALTER FAUNTROY. Chart 1, FEEDER MARCHES

Marchers from a number of groups will join Saturday's March on Washington by assembling at points around the city and walking together to the Mall; Chart 2, OFFICIAL CELEBRATION PROGRAM; Chart 3, METRO FARES AND OPERATING HOURS SATURDAY. Picture 5, Coretta Scott King and Rabbi Donald Peterman with 200 Atlanta Jews, gather at Dr. King's grave to show support for march. AP