Armando deMoya left Charlie's Restaurant near Fairfax City about 1:15 a.m. on Jan. 27 after drinking with friends, got into his fiance's green 1969 Chevrolet Impala and headed west on Lee Highway. A mile from his Centreville home, deMoya, a 19-year-old part-time student and contruction worker, either passed out or fell asleep.

His car, traveling at 70 to 80 miles an hour, swerved across three lanes, slammed into a drainage ditch and skidded 300 yards, shearing off a telephone pole. There were no witnesses. DeMoya, who was alone and not wearing a seat belt, was killed instantly.

DeMoya died in a manner that claimed the lives of more than 140 Americans yesterday and more than 50,000 last year alone.

Were those deaths and the accompanying $48 billion in damage the result of an airline crash or a nuclear accident, there probably would be a torrent of publicity, Congressional investigations and an outpouring of national grief and outrage.

By contrast the annual carnage on the highways and the 2 million injured each year evoke little reaction from a public numbed by body counts routinely computed over holiday weekends.

But those accidents devastate the friends and families of victims. "I can't begin to describe the pain," said Bonnie Kitzmiller, deMoya's 20-year-old fiance. "I was so angry at first, I kept thinking. Of all those stupid fools on the road, why did it have to be him?'"

Despite the millions of dollars spent on government safety campaigns and enforcement efforts, traffic accidents remain the leading cause of death for Americans up to age 34. One in 60 babies born today will die in a crash and two out of three will be injured.

"The public is indifferent and ambivalent about traffic deaths," said Brian O'Neill, research vice-president of the Insurance Institute for Highway Safety, a nonprofit scientific organization funded by insurance industry, which studies accidents.

"A lot of people are fatalistic," O'Neill said. "They think you put a St. Christopher on the dashboard and if your number's up, your number's up."

A 1979 study by a McLean consulting firm showed that one third of young drivers believe that their chances of being in an accident during the next year are 1 in 1,000. The actual ratio is 1 in 7.

But public overconfidence and ambivalence are only partly responsible for the rising death toll, says Joan Claybrook, administrator of the National Highway Traffic Safety Administration. The other factors: drivers are flouting the 55-mile-per-hour speed limit and are driving smaller, lighter gas-saving cars that frequently crumple in crashes, especially with larger cars and trucks.

"Manufacturers simply are not making cars as crashworthy as they could be," said Claybrook, who adds that Detroit has consistently fought federally-mandated safety standards like seat belts and collapsible steering columns, features she says have saved an estimated 30,000 lives in the last decade.

The auto safety effort has shifted radically in the past decade. Safety campaigns in the 1960s were predicated on what Claybrook calls "the nut behind the wheel" theory -- that only misfits are involved in or cause accidents.

The fact is that everyone is vulnerable. Most people drink and drive, speed, take risks, don't use seat belts and believe accidents are caused by someone's else's driving error, safety experts say.

Although he was driving a heavy, full-sized car, Armando deMoya was in many ways a typical accident victim, according to federal studies.

The person most likely to die in a crash is a 17-to 24-year-old male who has been drinking, is driving (too fast) an older, smaller, less well-maintained car on a two-lane road between the hours of 10 p.m. and 2 a.m. on a July weekend. Most fatalities, the studies show, are the result of front-end collisions; drivers crash into barriers, trees, utility poles or other cars.

Head injuries are the most common cause of death, because, federal officials say, less than 12 percent of Americans wear seat belts. Many die as a result of being thrown from the car or hurled against the windshield or dashboard.

DeMoya, whose body remained in the car and whose only visible injury was a small bruise on his cheek, died of a head injury. Doctors say the force of the crash crushed the part of his brain that controls breathing.

"What you have in many teen-age crashes is a young person learning to drink and learning to drive who doesn't handle either very well," said Charles Livingston, an associate administrator at the Federal Highway Safety Agency.

Alcohol is involved in at least half of all fatalities, particularly those involving young people. "The vast majority of the American public does drink and drive," said Livingston.

DeMoya had done precisely that, say his father, fiance and the friend who last saw him alive. "His friend swears they only had a couple of beers but Armando probably had more than that," said his father, Armando deMoya, a Washington Obsterician.

Whether deMoya was legally intoxicated is not known, because Fairfax County officials refuse to disclose the results of laboratory tests, claiming the information is private.

"If only I'd gone with him that night," said Kitzmiller, deMoya's fiance. "I'd never have let him drink more than two beers and I'd have made him slow down."

"Armando begged me to go with him that night," said Kitzmiller, in an interview in the neatly and inexpensively furnished townhouse the couple shared. "I was really tired from cleaning the kitchen and stuff so I said, 'No babe, you go have fun I'm going to bed.'"

DeMoya and another friend left the house at 11 p.m. in Kitzmiller's car and headed for Charlie's, a Fairfax restaurant frequented by deMoya, who unlike Kitzmiller, enjoyed going out drinking with friends.

Kitzmiller, who began dating deMoya when the two were juniors at Fairfax High School, said she plans to move from her Centreville townhouse to an apartment in Oakton. She recently got a part-time night job cleaning offices to supplement her full-time job at a nearby Roy Rogers Restaurant.

"I've just got to keep busy now," said Kitzmiller who said that her weight dropped from 110 to 89 lbs. shortly after deMoya's death. "I had my whole future planned with Armando," said Kitzmiller, who had dated him since she was 16. "I just wanted to be a housewife and have children."

Her biggest regret, she said fighting back the tears, was the abortion she had last year.

"Armando and I went and talked with his father who said we were too young to take care of a baby," she recalled in a quavering voice. "Now I wish I'd never agreed because I'd have something that was his."

The last time he saw his son alive was at Christmas, said deMoya, a Cuban refugee who was divorced from Armando's mother when the boy was six. "I kept thinking, if only i'd asked him for dinner that night," said deMoya who lives in Friendship Heights. "If only he was with me that night, if only I had spent more time with him, if only I were not divorced.

"Sometimes at night, when everyone else has gone upstairs to bed, I sit in the living room and smoke my pipe and look at a photograph of Armandito for a long time. That's when I think, if only . . ."

"Logically you expect to die before your children," said deMoya. "My attitude to my three children who are left is very different -- I have a keen awareness that, who knows, I might lose all three tomorrow."

Both Kitzmiller and deMoya say there were previous intimations of mortality: several months before his death deMoya confided to Kitzmiller's twin sister that he did not think he'd live to be 20 because he sensed he would die in a car crash.

Soon after he was 16 and had gotten his driver's license, his father recalled, deMoya wrecked his mother's Volkswagen one Saturday night on the George Washington Parkway while coming home from a Georgetown bar."The car flipped over three times but he walked away without a scratch," said deMoya. "I said, 'For crying out loud, if you drive, don't drink. If you drink, don't drive' and he said, 'Sure Dad.' But you know how kids are."

DeMoya said his son never wore a seat belt, a factor which, deMoya said police told him, would probably have saved his life. "I don't wear one either," said deMoya, shrugging his shoulders."As a physician I know I should, but I can't be bothered."

DeMoya's refusal to wear a seat belt even after his son's accident is not unusual, federal officials say. A recent study of post-crash victims showed that even those who suffered painful and in some cases crippling injuries often do not wear seat belts when they resume driving.

"There's a whole psychology of seat belt use," said O'Neill of the Insurance Institute. "Using them is an admission of vulnerability and people want to deny they are vulnerable."

Livingston of the federal safety agency agrees. "In the past people viewed highway safety as an entity separate and apart from normal human behavior. In reality the motor vehicle is just an extension of what society does."

Beginning in 1982 and phased in-over a three-year period new cars must be equipped with passive restraint systems, among them airbags which inflate in the event of an accident.

"That's why I like airbags," said Claybrook who estimates they could have saved 9,000 of the more than 30,000 killed last year in passenger cars."They don't distinguish between a good driver and a bad driver. They just do their job."

Other potentially life-saving measures for young drivers include the law passed last week by the Maryland General Assembly that will automatically suspend drivers' licenses of 16-and 17-year-olds who violate state drinking laws.

Next month a team from Claybrook's agency will spend six months studying the effects of fatal accidents on the families of victims, an area long ignored by previous safety research. "I think if people, including those in Congress, better understand the devastation these accidents cause, then they'll be much more likely to make auto safety a priority," said Claybrook.

"Armando's accident is the worst thing I've gone through in my life," Kitzmiller said. "If I have to go through anything like that again, I think I'd die."