Although beer and wine were available at half price, and drinks at the bar were double their normal size, Patricia Romano was satisfied with a glass of Perrier during happy hour at the Ha'Penny Lion Pub in the District.

"If I have a wedge of lemon or a lime in it, it looks like I'm drinking," Romano said recently, explaining that she often meets colleagues from a local construction firm at the bar, but has begun limiting her alcohol consumption.

Romano is not alone in altering her drinking habits. People are dramatically changing the way they drink, according to liquor industry sources who say the new sobriety is based not on morality or law, but on common sense.

As a result of increased awareness about drinking and driving, fear of drunk driving arrests and the general trend towards healthier habits, more people are opting not to drink in public or are taking special care not to get drunk when they do. Others are drinking more in their own homes or in neighborhood bars to avoid driving after drinking, according to liquor store owners and bartenders.

"There's no doubt about it," said Michael Maher, executive director of the Washington Restaurant and Beverage Association. "The public's drinking habits have changed."

Nationally, adult consumption of alcoholic beverages dropped nearly 9 percent in the past three years, according to the Washington-based Distilled Spirits Council, despite increases in the adult population. And the sales of hard liquor continued a decade-long decline, while beer and wine sales continued to rise. The amount of domestic bourbon alone on the wholesale market, the industry's major business indicator, fell 11.6 percent last year.

Business owners in the $66 billion alcoholic beverage industry blame the decline in sales in part on higher liquor taxes, but most agree that anti-drunk driving campaigns as vigorous as those against cigarette smoking a decade ago have been effective.

Bars and taverns have been the hardest hit in this self-imposed temperance, according to many.

In the Washington area, the amount of alcholic beverages sold in taverns and restaurants dropped "significantly" last year over 1984, according to Maher. The three-martini business lunch appears to be nearly a thing of the past and after 9 p.m., few drinks are sold, he said. Local restaurateurs and tavern keepers, who usually rely on as much as 60 percent of their profits from the bar, are feeling the effects, he said.

"There was a time when people came to a tavern to drink," according to Jeffrey Becker, spokesman for the National Licensed Beverages Association. "People come in now and order a club soda, a Coke or a Pepsi, simply to enjoy the social benefits," he said.

Norma Phillips, national president of Mothers Against Drunk Driving, said grass-roots campaigns promoting responsibility in drinking get much of the credit for the change in drinking styles.

"Groups like MADD have had quite an emotional impact, not just changing attitudes but, thank God, changing behavior," she said.

Some local bar owners said their businesses have not suffered from the change. "I don't see as big a decrease as everybody tells me I should," said Tom Russo, manager of Chadwick's in the District and Northern Virgnia. However, Russo said the taverns, like many others, have begun promoting meals instead of drinks to encourage business.

At Rumors nightclub in the District, the sale of wine coolers, a concoction of wine and fruit juices, has increased 55 percent in the last year, and nonalcoholic beers, wine and fancy nonalcoholic drinks are popular, according to manager Jim Lambert. It's common, he said, to see patrons wearing buttons pointing them out as designated drivers, allowing the driver in a group to a night of free soft drinks.

Customers are "much more cautious about what they drink and how they drink and are drinking closer to home," according to Jeffrey Bishop, who works at Rumors and has been a bartender for six years. "The neighborhood bar is making a comeback."

One of them, Mr. Henry's on Capitol Hill, is a place where the majority of people still order drinks at lunch, said manager Alvin Ross. The drinks poured throughout the holiday season, he said, "but then, most of these people were walking home."

Joseph McMahon, a Boston developer who spends two days a week in Washington, said he has altered his drinking habits recently. "I don't go out and drink in Boston; there I have to drive," McMahon said recently. "Here [in Washington], I just cab it."

The situation has posed a serious dilemma for the industry that makes its money from the sale of alcohol. Most liquor companies are using educational campaigns to encourage people not to "overreact" in their temperance but to learn how to drink in moderation. Some are even developing "alcohol management" campaigns to teach people how to calculate their drinking to stay outside of the legal definition of intoxication.

"People who are moderate drinkers are saying 'I'm not gonna drink at all tonight,' when in fact that isn't necessary," said John Burcham of the National Liquor Stores Association.

Consumer education is important because many people avoid, or consume, the wrong drink for the wrong reason, some say. Beer and wine are gaining more customers, for example, but contain as much alcohol per serving as a shot of liquor or a mixed drink.

Changed attitudes about social drinking were evident throughout the D.C. area during the holiday season.

Elbe Beer and Wine in Wheaton, which has many business accounts in addition to individual customers, provided beer for 30 fewer New Year's Eve parties than it did in 1984, and lees booze was purchased at the parties it did cater, according to Jeffrey Bobrow. Individual customers continued to buy. "People were just getting their bottles of champagne and going home," he said.

With encouragement from the Washington Board of Trade, scores of local businesses implemented holiday party guidelines that ranged from totally dry parties to posters reminding employes to be responsible.

The Federal National Mortgage Association in Northwest Washington sent letters to 1,700 employes asking them not to drink and drive, reminding them that an employe was killed the year before in a drinking-related accident.

And Boland Trane Services Inc., a Rockville-based firm, closed the bar early during its Christmas party for 150 guests at the Congressional Country Club.

"In years past, there was an awful lot of drinking going on," said Louis Boland, Jr., who offered guests coffee and black bean soup after 10:30 p.m.

He explained the corporate decision this way: "With all the roadblocks, you don't want to see your employes lose their licenses."