The Nation's Capital will finally permit right turns on red, beginning Dec. 17, but motorists will only be allowed to make the turns at 805, (or 17.8 percent,) of the 4,519 approaches to city traffic lights.

Most of these approaches are in outlying areas of the District with few of them downtown or in densely populated neighborhoods.

The small number of approaches to intersections where right-on-red turns will be permitted apparently will make Washington the most restrictive place in a nation that now almost universally allows right-on-red turns to help conserve gasoline.

Spurred by federal energy and highway officials, all states and cities -- except New York City -- now permit such turns at the vast majority of intersections. Washington has long opposed right turns on red here but bowed to pressure in the form of the threatened loss of $340,000 in federal energy conservation funds.

Many motorists already are making right-on-red turns here, illegally, even before the new law goes into effect. District transportation officials fear that the number of intersection violations will increase after Dec. 17 -- possibly from motorists' frustration at the small number of right-on-red turns that will be permitted.

"Federal officials are surprised and have been a little caustic because so few will be permitted here, and the American Automobile Association also contacted us," Steward Cross, deputy assistant director of the District Department of Transportation, said this week.

"The District definitely is interpreting the guidelines (for not allowing right-on-red turns) too conservatively," observed Don Ryan, chief of the Federal Highway Administration's signs and markings branch. "And we've already asked them to go back and restudy the intersections and put in time restrictions where appropriate."

Local AAA public affairs director, Glenn Lashley, said this week "we're concerned the District is doing it in so few places. When Maryland and Virginia adopted right turns on red, we felt the city should also try to be uniform . . . and now we feel the city should embrace the spirit of the law."

"It's true we are permitting only a minimal number of right-on-red turns," Cross said, "but we are concerned about the safety of pedestrians." Especially, he said, since Washington has heavy traffic, large numbers of tourists unfamiliar with its streets and a high pedestrian death rate.

So far this year, 20 of the city's 42 traffic fatalities have been pedestrians, roughly the same 48 percent pedestrian death rate the District averaged over the past four years. New York City has the nation's highest pedestrian death rate, a four-year average of 52.5 percent of its traffic accidents. Washington ranks fifth, but more than a dozen cities have rates above 40 percent.

Federal transportation officials, like Ryan, insist that right-on-red turns have not increased accidents and deaths in cities where -- they are now permitted and that the turns definitely speed up the flow of traffic and save gasoline.

However, there have been no definitive studies on how much gasoline is saved by right on red or whether accident rates are affected by it. The only study cited by federal officials is a 1977 Virginia Highway Research Council study that estimated the turns would save 3.5 million gallons of gasoline a year in the state, which was then just initiating right on red.

As for not increasing accidents, the District's Cross says most accident reporting systems and police tickets do not single out right-on-red accidents and arrests, which are therefore not reflected in computerized city and state statistics. "That's why the District is now changing its accident forms and tickets . . . we'll be able to tell what effect it's having," Cross said.

District police plan a special crack-down on intersection violations starting Dec. 17, to help prevent traffic accidents and violations of the right-on-red law, Cross said.

The number of right-on-red turns permitted in Washington may be increased slightly after the system goes into effect, Cross said, but the number probably will not rise much above 20 percent.

However "time limitations" for some right-on-red turns will be instituted at many intersections in the District within a year. This would allow the turns before and after school hours at many intersections near schools, and at other intersections in non-peak traffic hours.

After finally agreeing to institute right on red here, District officials initially sought to use a system once instituted, but now discarded, in states like Maryland and Virginia. It was the reverse of the now standard law and permitted right-on-red turns only at intersections with signs saying "Right on Red Permitted," Federal Officials and organizations like the American Automobile association urged a uniform law to avoid confusing all states.

The District has completed detailed studies of each of its 1,250 intersections with traffic lights -- there are more than 7,000 intersections in the city -- to determine where right on red should and should not be allowed.

Right turns on red will be permitted at 805 of the 4,519 approaches to the 1,250 intersections with traffic lights, and "No Turn on Red" signs are being installed at 3,103 approaches. There are 611 approaches to traffic lights on one-way streets, T-intersections or intersections with yield signs where right-on-red turns are not feasible.

Permitting the turns is not required by federal law, but is included in the nation's model traffic act, the Uniform Vehicle Code. Permitting them was required in the 1975 Oil Policy Act for states -- and the District -- that wanted to share in $77.5 million in federal energy conservation funds.

The $250,000 cost of studying the District's intersections and installing more than 3,000 signs will be paid almost totally from the city's annual allocation of federal highway money. The direct cost to the city will be between $10,000 and $20,000, according to D.C. officials.