An additional 402 city blocks with at least 7,452 parking spaces will be put off limits to commuters next month in the biggest single expansion of Washington's residential permit parking program.

Resolutions approving the expansion were adopted unanimously last week by the D.C. City Council.

The largest neighborhood affected is 78 blocks in the Dupont Circle area on the northern fringe of downtown, currently a favorite area for all-day commuter parking. The new ban will extend eastward from 23rd Street NW to Logan Circle, at 13th Street, and from M Street north to U Street.

Part of the area already is restricted by short-time parking meters and rush-hour towaway zones.

Douglas N. Schneider Jr., director of the D.C. Department of Transportation, reported recently that a survey of the Dupont Circle area showed 100 percent of 1,935 legal parking spaces in the 78 affected blocks were filled during business hours. Of the parked cars, 53 percent bore license tags from outside the District of Columbia.

And for every 100 legally parked cars in the Dupont Circle area, there were seven that were illegally parked.

Schneider has been a crusader against individuals commuting one to a car, and an advocate of a shift to mass transportation and to car pools.

With the new restrictions, more than 11 percent of the city's 10,000 block will be covered by the residential parking ban. Other large chunks of the city, including downtown, are covered by meters and other restrictions.

Other areas of the city affected by the newly expanded parking restrictions will include the western fringes of both the American University and Howard University compuses, impacted by all-day student parking, and the areas adjoining Metrorail stations on the Red Line at Takoma, Brookland and Fort Totten.

Areas around the future Cleveland Park and Minnesota Avenue NE subway stations also are being put under the restriction.

So are areas around two Metrobus garages - at 14th and Decatur streets NW and at Half and M streets SE - where bus drivers park their cars for extended periods.

The block of Atlantic Street SE just east of South Capitol Street, the location of an important bus terminal, also will be restricted.

The Transportation Department said the expanded parking restrictions will be put into effect in the various neighborhoods in three stages during August. Residents will be notified by letter of the dates and of the permit-sticker sales locations. For communters, the only notification will be the erection of signs.

Under the rules, neighborhood residents must buy parking stickers costing $5 a year that permit them to park anywhere in the ward where they live. A sticker valid for Ward 3 (west of Rock Creek Park) will not permit such parking, for example, in Ward L (which includes Capitol Hill).

Nonresidents of a ward, whether D.C. residents, suburbanites or tourists, are limited to two hours of parking.

Under D.C. rules, the residential parking restrictions were initiated by petitions signed by neighborhood residents.After the petitions were submitted, the Transportation Department held neighborhood forums. Once satisfied that residents understood and wanted the restrictions, the department recommended the restrictions to the mayor, who in turn asked the council to enact the resolution that put them into effect.

Commuters affected by the ban had no direct voice in the decision-making.