The District of Columbia grudgingly joins the rest of the nation tomorrow in permitting motorists to make right turns after stopping at red traffic signals.

While the new city regulation is identical to the rules in Maryland and Virginia, such turns in the District will be permitted at only 805 -- or about 18 percent -- of the city's 4,519 approaches to traffic lights. 8

Intersections at which right turns will be prohibited are marked with signs reading, "No Turns on Red." These signs have been masked, but the cardboard covers are being removed this weekend.

The signs have been erected at all intersections in the downtown area and at outlying intersections where visibility is impaired, where there are exclusive pedestrian "walk" signals and where many school children or elederly and handicapped pedestrians cross.

Douglas N. Schneider Jr. director of the D.C. Transportation Department, stressed that every motorist must come to a full stop at a red signal before making any legal right turn.

Schneider said a lower proportion of District intersections qualify for unrestricted right turns because of the city's large number of street trees and its unique layout, with numerous diagonal streets and traffic circles.

The right-turn-on-red procedure is required under federal regulations as a gasoline-saving measure.

Its adoption in the District ends a two-year dispute with federal officials and Congress. Federal officials overrode a city proposal to permit right turns only at intersections where signs would say they were allowed.

Among other major cities, only New York and Boston do not permit right turns on red.