Mary Beth Nutter, a 26-year-old sales representative, wants to meet that special man. But like many Washington career women, she has neither the time nor the taste for singles bars, traditional dating services or personal ads.

Bars? "It's not that I'm a shy person; I just don't like being that much on display," she says. Dating services? "God only knows who calls you." And, the personals? "Sorry," she concludes, "but I'd rather sit at home for six months."

Like most Washingtonians, she spends an inordinate amount of time not sitting at home, but in traffic snarls. Now, she thinks she has found a way to make beltway cruising fun and perk up her social life, too. Mary Beth Nutter has joined a highway dating club.

"My friends are using me as a guinea pig," she says. "But it does seem like a good idea."

There is a growing number of such clubs around the country, but the idea is new to Washington. At least three have sprung up here recently, advertising such slogans as "Don't Let the Fun Pass You By," or "The Fastest Moving Singles Club in Town."

Why go to Clyde's or Champions, and why place "Trim, Witty SWF" ads when you can check out the market from the privacy of your own automobile? Or so the theory goes.

Nutter's club is called Road Oners. It was started last month by Tricia Greer, 30, who has a background in publications, and a longtime friend, Donna Check, 34, a medical equipment salesperson.

They dreamed up highway dating several years ago when both were recently divorced and eager to date, but not thrilled about twirling swizzle sticks at a singles bar and waiting for somebody to approach.

"We had had the experience of sitting at a stoplight, you glance at the person next to you -- maybe you get a smile, make eye contact -- but the light always turns green and you drive off, and that's the end of that," Greer said.

It wasn't until they read a People magazine story about a highway dating club in California that they decided to get serious and test the Washington market.

They spent most of last August dropping in at the city's singles bars, asking whether the idea could fly here.

The answer was "Yes," with conditions. Most singles interviewed said they would refuse to slap a bumper sticker on their car, the accepted way of identifying highway club members. "They said 'Bumper stickers are tacky,' " Greer said.

So the women decided to use small window decals instead. They let the bar crowd choose the winning design: a black highway disappearing into infinity, symbolizing the limitless dating possibilities to be found on the Capital Beltway or Shirley Highway.

And while Washington's singles seemed desperate for companionship, they considered it uncool to be so obviously on the prowl. "So we intentionally made the decal so it didn't say 'I'm single and looking,' " Greer said.

Their club opened in October. So far, the women claim to have 240 area members, most of whom are professionals. Their goal is to attract 3,000 fender-flirting singles by the end of December.

Here's how it works: members pay $40 a year, are given window decals, and submit a personal profile that is kept at Road Oners headquarters, located in Check's D.C. home.

If, for example, a man spots a fellow club member in traffic and likes what he sees, he jots down her license plate number and telephones a special "Spotline" number.

The club arranges to exchange personal profiles, but it's up to the second driver to make the first phone call. That way, Greer says, nobody is asked for a date who doesn't want to be.

Nutter has been scanning the highways since she joined, but so far hasn't spotted any other cars with Road Oners decals. She has been in the club for only two weeks, though, and is confident that sometime soon, a decent man will cruise by.

"I'm not looking to get married, by any means," she says. "It's just that it would be nice to meet someone that possibly had the same interests as you. A friend."

Glen Gilbert of Silver Spring, another Road Oners member, has had more luck. The 39-year-old computer programmer last Sunday spotted an appealing woman in a Crystal City parking lot, and has arranged a date with her.

At the very least, he says, his highway dating club will alleviate the boredom of spending an hour and a half each day commuting to and from work in his 1985 red Subaru. Now, he has something to look forward to when traffic grinds to a halt. "I like it," he says. "Hey -- I'm jazzed on it."

Perhaps highway dating is an idea whose time has finally come in Washington.

That apparently wasn't the case when George Martin, 30, of Gaithersburg launched his D.C. I-95 Singles Society nine months ago. He tried and tried, but couldn't get it to work as well as he hoped and it folded in August.

He knew highway dating was a fad in Los Angeles, and reasoned it should work well in traffic-snarled Washington. "But here, I got the feeling that people didn't want to put bumper stickers on their cars because it was going to mess up their car," he said.

Another club, which uses bumper stickers, Data Friends Service of Lanham, also has had mixed results, said Theodora Britton, 36, who has been in business since April. She, too, hopes business will pick up.

"In Boston it seems to be doing well, and I heard Atlanta is doing great, but what happened to the capital of our country?" she asked.

Not to worry, says Road Oners' Greer, whose basis for comparison is Richmond, where she used to live. She maintains that the idea is catching on so quickly, she'd eventually like to expand it to the Metro.

With subway dating, rush-hour singles who lust after each other's briefcases and Burberrys could do more than sigh when the doors spring open at Metro Center.

The problem, Greer says, is how to identify oneself as available underground.

"A lot of people wouldn't wear a blatant badge, and that's the only way we can think of doing it," she adds. "We thought about umbrellas. An umbrella would be perfect. But not everyone carries one every day. Although it seems like, lately, it would have been great."