When retired truck driver Mel Pearson was stopped by Prince George's County police early one Sunday morning in June and charged with driving while intoxicated, he thought he would be sent to jail. Pearson, 62, had already been convicted twice of DWI, and on this night, driving home to Ruther Glen, Va., after visiting his daughter in Baltimore, he was quite drunk.

"When I saw the police lights in my rear-view mirror, I thought, hell, I'm going to jail," he said. "I've never been behind bars before, and that place the Prince George's County Detention Center is rough. I was scared."

But Pearson, who was convicted of driving while intoxicated and driving without a license, was not sent to the county detention center. Instead, he was sentenced to serve 21 days at Prince George's new combination jail and alcoholism treatment facility.

The facility, which opened Aug. 2, is the first in the nation to combine incarceration and treatment of DWI offenders in one specialized structure.

Bruce Orenstein, director of the facility, said it was created because of a growing feeling that while DWI offenders ought to be punished for their actions, they should be treated for their alcohol problems.

Orenstein said the facility is also intended to help alleviate overcrowding at the county detention center, already under court order to reduce its inmate population.

"The idea is to assess and diagnose to what extent a person has an alcohol problem, and then try to prescribe an effective long-term treatment program," said Orenstein. "We know we can't 'rehabilitate' them -- that is not our intent."

The new $1 million building, paid for jointly by the state and the county, sits unobtrusively among the cornfields of Upper Marlboro. To a first-time visitor, the one-story structure, which can accommodate 50 men and 10 women, resembles an overnight camp more than a jail. There are no bars on the windows, and residents (they are not called "inmates") wear street clothes and move about freely. They sleep on cots in large, dormitory-like rooms and spend their free time playing cards or watching TV.

Del. Pauline Menes (D-Prince George's), who championed efforts to get the legislature to fund the facility, said its unique nature means its success or failure will be closely watched. "It is almost a national trial effort," she said. "Indications are it will be fine, but it's still too early to tell."

Mel Pearson, however, said he already knows the facility is a success. "This is a beautiful program," he said. "You can learn a hell of a lot here. They teach you what that damn stuff will do to you. Now I know I can't take that first drink. I can't handle it."

Alan McDowell, a burly 21-year-old who has been in and out of prisons since his teens and started drinking beer at age 9, also endorses the facility. "This place is a lot better than jail, I'll tell you that. You couldn't ask for nothing better if you're in trouble," he said. "They give you all the attention in the world and drive it into your head: drinking messes you up."

McDowell, of Southeast Washington, said he drank more than a case of beer daily before being jailed. He said the program works because it "takes your mind off drinking and puts it on your life style -- how you want to live, how you need to live."

Residents stay at the facility for seven, 14 or 21 days and pay $34 per day. They work during the day and attend alcoholism treatment programs at night and all day on weekends.

Residents are given a battery of tests on arrival. "The idea is to find out everything we can about each person and assess how much of a problem they have," said treatment director Eileen Schock.

Schock said the program seeks to get residents to come to grips with the fact that they have problems with alcohol. "We feel that if they participate in their own diagnosis, rather than just giving them a test and saying, 'You are a problem drinker,' we have a much better chance of success in finding an appropriate long-term treatment," she said.

Whenever possible, residents also participate in a work-release program, in which they continue at their present jobs, provided that their employers agree and that they return to the facility by 6 p.m. If they are unable to participate in the work-release program, they work for the Department of Public Works, picking up trash along county roads or mowing grass. Those who are retired or unable to work stay at the facility and do maintenance work and help prepare meals.

Residents who are permitted to leave the facility must take a breathalyzer every time they return, said Valerie Miller, work coordinator for the program. If any trace of alcohol is found, or if they are late, they can be removed from the program and sent to the county detention center, she said.

While the treatment program includes films and lectures, residents say the most effective treatment comes during the Alcoholics Anonymous-style group therapy sessions.

"It keeps you off the pity pot," said Pearson. "I don't care what problem you have, you can talk to someone who can relate. It's different than talking to your family or your pastor; alcoholics understand. You trust them and they trust you."

Tony Woods, a bearded 21-year-old from Beltsville, agreed. "Everybody in here has a problem with drinking," he said. "You're put in a group where you can bring out your emotions. People understand. And they'll tell you you're full of bull if you are."

Like Pearson, McDowell is convinced that the program has worked. "I already know I'm not going to drink," he said.

His friend Woods, seated next to him, was less certain. "I'm just going to take it one day at a time," he said