Cam Johnson and her husband had donated money to campaigns against drunken driving. They often talked to their three children about its dangers. And Johnson, 32, rarely drank alcohol other than a sip of champagne on New Year's Eve.

But on a September night last year, the Herndon mother attended a birthday party at a D.C. restaurant. Prodded by her girlfriends, she said, she ordered a Remy Martin cognac and Coke. Her friends had drunk more, so she volunteered to drive them home.

"I thought, I'm doing a good thing here," she said. "But then, it backfired on me."

Johnson was arrested on the Reston Parkway when she drove her BMW through a yellow light at 4:30 a.m., she said. A petite woman, her blood alcohol level tested at 0.09 -- 0.01 above the state legal limit. She became one of the 27,000 Virginia drivers convicted last year of driving under the influence of alcohol or drugs.

As Virginia and other states across the country tighten laws against DUI offenses, the legal ramifications of an arrest are becoming more serious and more predictable. But the personal fallout is harder to measure.

A DUI arrest sent Dondi A. Randolph, an Alexandria man working to become a plumber, into a financial crisis. For State Department retiree Robert Alexander, it has meant depending on friends to drive him on every errand. One man said he agonized over how to explain to his children why he couldn't coach the Little League team after losing his driver's license.

For some, it can bring public embarrassment and loss of livelihood.

Rebecca L. Perry's job as Alexandria's school superintendent was jeopardized after her DUI arrest in April. And Dulles security chief Charles Brady resigned after admitting that he was driving drunk on New Year's Day while he was supposed to be overseeing airport security during a Code Orange terror alert.

The hardships associated with a DUI conviction pale when compared with the loss suffered by the families of the 17,000 Americans killed every year in crashes involving drinking drivers. Drunk drivers don't get much sympathy.

To gauge the effect of a DUI arrest on the lives of ordinary people, The Washington Post examined the court records of 92 drivers -- everyone arrested during a one-week period last September in Fairfax County, the region's largest jurisdiction. Their stories offer a look at the often painful consequences of an arrest, even before Virginia's stricter laws went into effect July 1.

The majority of those arrested -- 74 of 92 -- were, like Johnson, charged as first-time offenders. And almost all the first-time offenders received the same sentence: losing their license for a year. Most were permitted to drive to such specified places as work, school and medical appointments. Most paid a few hundred dollars in fines. Eight of the first-time offenders spent time in jail.

Many who received a DUI conviction said its huge financial costs and burdensome restrictions upended their lives.

Johnson said she lives with the consequences of that one drink.

She feels like an outcast in her own family. Her marriage has collapsed, in part because of arguments about the thousands of dollars her arrest has cost. She described the experience as the most wretched ordeal of her life.

"I've been through hell these last seven months," said Johnson, who fled Vietnam at age 6 with her mother and sisters.

Nearly a year after her arrest, she has admitted she made a mistake, yet she still can't believe her single drink was excessive.

Charles Lieber, director of the Alcohol Research and Treatment Center at the Bronx Veterans Affairs Medical Center, said women and Asians have a limited ability to tolerate liquor. Compared with men, women produce less of a stomach enzyme that breaks down alcohol. Many Asians also lack a second enzyme that rids the body of alcohol toxin, meaning a single drink can cause flushed skin and elevated blood alcohol levels, he said.

Johnson's difficulties were magnified when she missed a court date because of a misunderstanding with her attorney, she said. A bench warrant was issued for her arrest, and she wound up in jail. It was "the worst experience of my life," she said.

In jail, she used her hands to drink water from a sink atop a steel toilet unit. Her bologna sandwich came with a thumbprint. She would call home to get the time because there was no clock in the cell.

"I was there for two days. I cried for two days," she said recently, still stunned at the turn of events. "I'm a mother of three. I'm in the cell with people who did fraud, with people who steal cars, robbed a 7-Eleven. Everyone is together until their hearing. Here I am, I just missed my court date, but [I'm] in there with drug dealers."

Eventually, Johnson pleaded guilty and paid $365 in fines and fees. Her license was suspended for a year, but she is allowed to drive to and from classes she is taking to become a nail technician, and to transport her children to school. Johnson also paid about $4,000 in attorneys' fees at a time when she and her husband had purchased a new house and had many bills.

"My husband thinks I threw away $4,000," said Johnson, who believes her arrest contributed to arguments that ultimately led to their separation.

Nobody in her family drinks alcohol, she said, adding to her feeling of estrangement.

"They look at me like I'm an alcoholic," she said. "Everyone looks at me like I'm a criminal."

Some first-time offenders said they drank too much because of an emotional crisis, then were caught driving while in that condition.

Lawrence P. Robinson's girlfriend had just ended their 14-year relationship. Robinson, 53, was devastated and on antidepressant medication. He went to a bar and drank four small glasses of white wine, he said, then headed home in his Nissan Maxima. Robinson said he had his cell phone pressed to his ear, weeping as he begged his girlfriend to take him back. He was about two miles from his house in Herndon when police stopped him for driving erratically, according to court records. His blood alcohol level was 0.14.

Robinson pleaded guilty and paid $465 in fines and fees. He is permitted to drive to jobs for the cleaning company he operates. But shortly after his conviction, he lost a secondary job. And his DUI made job interviews awkward.

"It's embarrassing for someone my age to tell a prospective employer that I had a conviction," he said.

For Burke resident Robert Alexander, 70, the crisis began last August when his doctor told him that he might have lung cancer, which turned out to be a false alarm. But that weekend, the retired State Department employee went to a Labor Day party, he said, where he drank some beers.

Then he got behind the wheel of his GMC Yukon, and though another driver struck him, Alexander, with a blood alcohol level of 0.17, was charged with drunken driving, records show.

Alexander pleaded guilty, paid $515 in fines and lost his license for a year. As a retiree, he can't get a restricted license, so he relies on friends to drive him everywhere, including the supermarket and church. He has given up competing in golf tournaments because he can never be assured of a ride. His car insurance premiums will triple.

"It's really hard," he said. "My friends, thank God, they have taken care of me."

Others struggle to recover from the financial burden.

Dondi A. Randolph's downward spiral began the day he received DNA test results that showed that he was not the biological father of his 11-year-old son. That night, the plumber's apprentice went to a Ruby Tuesday restaurant and drank two strong mixed drinks -- Bombay Sapphire gin with a splash of grapefruit juice, he said.

Police stopped him about 10:30 p.m. Sept. 2 on Richmond Highway, with a broken taillight and no headlights on. The police report described him as incoherent and confused. His blood alcohol level was 0.15, according to records.

Randolph, 36, pleaded guilty. But he couldn't pay his $572 fine and court costs, even after the judge said he could make deferred payments.

As a result, he couldn't get a restricted license to drive to work and school. Desperate not to miss plumbing classes that he had paid for, he got in his car and headed to school anyway. Police caught him behind the wheel twice, and the fines piled up to more than $2,500. He couldn't pay his attorney. He fell behind on his rent, triggering eviction notices. Eventually, he abandoned his 1980 Cadillac because the impoundment fees exceeded its value.

It was particularly hard explaining the situation to his children.

"Daddy made a mistake," he told his 11-year-old daughter. "Daddy can't drive."

Yet Randolph has grown to consider his arrest a wake-up call. He said he has stopped drinking liquor. He continues to attend school. Some mornings, he rises as early as 3:30 to catch two buses and three trains to a job site 31 miles from his garden apartment in Alexandria.

In all, Randolph has run up more than $4,400 in bills related to his arrest.

The typical cost of drinking and driving in Virginia ranges from $5,000 to $20,000, according to a 2003 study by the Thomas Jefferson Community Criminal Justice Board in Charlottesville, a group of law enforcement officials.

In addition to attorney and court fees, drunk drivers usually have to pay for car towing, restricted licenses and reinstatement of their regular licenses. Everyone is ordered into the alcohol education program that, in Fairfax County, costs at least $400. Repeat offenders and the "super-drunks" -- those with a blood alcohol level of 0.15 or more -- are required to install ignition interlock equipment on their steering wheels, at a cost of $450 for six months.

Pat Bowman, a counselor at the Fairfax Alcohol Safety Action Program, often asks those in the program, most of them professionals, to list the time and the money they have spent since their arrest. It averages more than $10,000.

"It's amazing," she said. "They could have taken a cab for $50."

Juan Angel Melgar Urbina has not been able to accept overtime work since his arrest Sept. 4.

Melgar is a bricklayer who came to the United States 10 years ago from Honduras, where he was a farmer harvesting corn and beans. He sets aside a portion of his income to send to Honduras for his two children and his parents. He lives in Herndon in a split-level frame house with his wife and young son.

He described himself as "not much of a drinker," but after a long day's work in Manassas, he said, he went to a bar with co-workers and had three beers. When police pulled over his Nissan Pathfinder less than two miles from his home, Melgar's blood alcohol level was 0.12. He pleaded guilty, paid $475 and had his driver's license suspended for a year, though he is allowed to drive to work within a narrow time frame. His out-of-pocket costs exceeded $1,600 for an attorney, fines and fees.

He said he knew it was illegal to drink and drive. But in Honduras, he said, drinking drivers could settle the matter on the spot by pressing some cash into the hands of the police officers who stop them. His co-workers shrugged it off. "They got you," said one, who himself had been arrested on another occasion. Since his arrest, Melgar said, he has consumed no alcohol.

"One brings this upon oneself," he said, speaking in Spanish. "Who am I going to be angry at? If they caught me, it's because I did something and have to pay for it."

For Muktar Ali Yahia, drinking had been a weekend activity since high school. The 27-year-old garbage collector comes from a Muslim family in which alcohol is considered a sin, but many of his friends were drinkers.

He said he had consumed two or three beers Aug. 31 when he was arrested by police. His Nissan SUV was weaving between lanes, court records indicate. His blood alcohol level was recorded at 0.12, and he pleaded guilty. He paid the court $475, but he estimated that his DUI cost him about $4,000.

Today, Yahia frequently takes public transportation. Instead of going to clubs, he goes to his mosque to pray, he said. And he has a new circle of friends.

"I don't do what I used to do," he said. "I don't go out. I stay home on weekends and watch TV. Before, I'd hang out with friends. I don't know if they understand. I tell them I don't have a license, so I can't see them."

He said he has abstained from drinking since his arrest.

"It was an expensive night," he said. "And I never want to have a night like that again."

Staff writer Lila Arzua, database developer Jacqueline Dupree, database editors Dan Keating and Sarah Cohen and staff researcher Bobbye Pratt contributed to this report.

Dondi A. Randolph of Fairfax County, whose license was suspended after a DUI conviction, takes two buses and three trains to get to work.Virginia Gov. Mark R. Warner (D) at the bill-signing ceremony in May for the DUI-related legislation.