After a tumultuous eight months in District politics, voters go to the polls on Tuesday to nominate candidates in the races for mayor, D.C. Council chairman, two at-large and four ward council seats, D.C. delegate to Congress and the new shadow lobbying posts.

Change is the watchword in the primary elections next week, the first time since 1978 that Marion Barry will not be running for the Democratic mayoral nomination. Not only do the primaries signal the end of the era of Barry as mayor, they set the stage for the November election of the first new council chairman in eight years, the first new delegate in nearly two decades and, for the first time, the so-called shadow senators and representative.

Polling places in the District's 140 precincts will open at 7 a.m. Tuesday and close at 8 p.m. The deadline for registering to vote in the primaries has passed, as has the deadline for requesting absentee ballots for voting by mail.

Under the District's system of closed primaries, only those voters registered in the city's major political parties -- Democratic, Republican and D.C. Statehood -- may cast ballots to nominate candidates from those parties. Voters also may write in candidates.

All registered D.C. residents may vote in the general election Nov. 6. The deadline for registering to vote in that election is Oct. 9.

Boosted in part by changes in the law making it easier to register, the District has a near-record number of registered voters: more than 296,000. About 260,000 of those are eligible to participate in their respective party primaries: 231,000 Democrats, more than 26,000 Republicans and about 2,500 D.C. Statehood Party members.

The winners of the Tuesday primaries will appear on the November ballot, along with any independent or minor party candidates who qualify.

The primaries next week are winner take all, meaning there will be no runoffs in individual parties. Given the makeup of the D.C. electorate, some elections on Tuesday will be decisive.

For example, the winner of the Democratic primary for D.C. Council chairman may expect scant opposition in the fall, because candidates from neither the Republican nor D.C. Statehood parties appear on the primary ballot.

Similarly, the GOP and Statehood Party fielded no candidates in the primary elections for the council seats representing Wards 1, 5 and 6, according to city elections officials.

Whoever wins the five-way race for the Democratic mayoral nomination will face the Republican mayoral nominee, who is unopposed for his party's nomination.

The winner of the Democratic nomination for at-large council member will compete in November against the Republican and Statehood Party nominees, as well as several independent candidates, for two at-large seats on the 13-member council. The two top vote-getters in the fall will win those two council seats.

Also in November, voters will elect a new at-large member and a new Ward 4 member of the D.C. Board of Education, as well as three other ward members of the school board. All 323 seats on the city's Advisory Neighborhood Commissions are up for election this fall.

The two shadow senator positions and one shadow representative post, which are local lobbying offices created by the D.C. Council, will be listed on the primary ballot by their federal titles: "United States Senator" and "United States Representative." Voters may cast up to two ballots for senators in the primary.

After many years of debate about statehood for the District, council members voted earlier this year to create the three positions, primarily to lobby the House and Senate for statehood. The city provided no public money for those offices.

The D.C. delegate's job pays $125,000 annually, and the office of mayor pays $90,705 a year. D.C. Council members receive annual salaries of $71,885 for their part-time posts; the full-time chairmanship pays $81,885.

Polling places in the precincts should be accessible to physically disabled people, and city elections officials said they plan to provide "curbside" voting for those needing special transportation to and from the polls.

In addition, the city will provide special telephone communications for the hearing impaired through a service number, 639-8916.

For more information about voting and arrangements for the physically disabled, residents can call the D.C. Board of Elections and Ethics, 727-2525. Office hours are 8:30 a.m. to 4:45 p.m.