District police last week decided to try psychology to help preserve Washington's large but endangered species the pedestrian.

Instead of punishing "bad" pedestrians with $5 tickets for jaywalking and disobeying traffic signals - more than 7,000 pedestrians were slapped with these signs of District disapproval in 1976 - police last week handed out to "good" pedestrians almost 1,500 award tickets, entitling them to a free sandwich at a local fast-food chain.

The carrot instead of the stick idea was tried because despite the crackdown on pedestrian violations last year, Washington had one of the highest pedestrian death rates in the nation. And pedestrians are being killed and injured by cars at an even higher rate so far this year.

Fifteen of the District's 25 traffic deaths to date, 60 per cent, have been pedestrians and more than 360 pedestrians have been struck by cars and seriously injured, almost all in the downtown business district.In 1976, 34 of the 56 persons killed on Washington streets, or 57 per cent, were pedestrians. Nationally about 7,500 pedestrians were killed by motor vehicles last year or about 16 per cent of the country's total 45,000 traffic death toll, according to preliminary figures of the National Highway Traffic Safety Administration.

Those pedestrians rewarded last week with a free 85-cent Egg McMuffin sandwich at any McDonald's restaurant in the District, were almost all somewhat apprehensive when approached by police officers with books of tickets in their hands.

"What did I do, officer?" they almost invariably asked.

"You're being rewarded this time. We've had so many pedestrians killed that we're giving out awards to those who obey traffic signals . . . this ticket entitles you to a free Egg McMuffin at any McDonald's," said Officer Elaine Woody to many of the more than 70 pedestrians she stopped at the intersection of Connecticut Avenue and K Street NW during rush hour last week.

"Oh, wonderful . . . but I can't take it, I'm on a diet," said Betty Brown, a Silver Spring public relations consultant who had waited in a crowd of pedestrians for the walk sign before trooping across Connecticut Avenue.

"I sometimes jaywalk like everyone else," Brown confessed, "but even obeying all the traffic signals I come close to getting hit by cars almost every day. Motorists don't yield to pedestrians here and they just don't care."

Officer Woody agreed that Washington motorists are aggressive. "I'm supposed to give some of these things to motorists who yield to pedestrians in the corss walks but you can get run over trying to reward them," she said.

District police rarely issue tickets to motorists for failure to yield to pedestrians, except when they actually hit them. During 1976, while tickets were being given to 7,000 pedestrians who ventured illegally into city streets, only 243 tickets were given to motorists who violated pedestrian crosswalk regulations. And in two of the months police issued only one and three such tickets.

One reason so few motorists were ticketed, said J. W. Lanum, who coordinated the Egg McMuffin pedestrian campaign for the D.C. transportation department, is that the present penalty is "excessive . . . police aren't giving tickets and the courts aren't convicting motorists when they do." A motorist who fails to yield to a pedestrian not only is fined $25 but is assessed 5 points for the offense. If he actually hits the pedestrian he is assessed only 3 points, and fined $25, unless the pedestrian is hospitalized in which case he is fined $100. The city is the process of reducing the 5 point penalty to 2 points, Lanum said. Under the city's point system, a motorist's license can be suspended if he accumulates 8 points, and revoked if he receives 12 points during a year.

The egg sandwich reward for pedestrians, and the pedestrian award tickets, were offered by McDonald's after city officials approached the firm, Roy Rogers and several other fast-food chains to see if they were interested in helping "reward positive action instead of punishing negative bahevior," said Lanum. "We had some problems about the commercialism of it, but McDonald's name is mentioned only once on the tickets and that's in small print."