When American Express executive Mark Ryan works from home, he just has to tell his 2-year-old daughter one thing to keep her quiet.

"If you don't let Daddy do his work, he's going to have to go to stinky New Jersey."

His warning works. She knows the trip to New Jersey takes more than two hours, and that if he had to work in the office, he'd return past her bedtime.

Mr. Ryan, whose company was displaced by the Sept. 11 terrorist attacks, is a new fan of telecommuting. Ideally, he would like to work at home part-time, even after American Express' downtown office reopens this spring.

The last six months have given hundreds of thousands of New Yorkers a taste for telecommuting. Supported by technology that became available just last year, people like Mr. Ryan are likely to fuel what was already a growing demand for work-at-home schedules.

"It's inevitable that telecommuting will rise," said Anne Chamberlain, who advises clients on employee retention strategies at Buck Consultants Inc. in Manhattan. People have become more comfortable working over longer distances, while employers anxious to hang on to talent despite the economic slump are searching for cost-effective ways to keep them happy, she said.

A growing number of employees have been using the information highway to bypass daily commuting for at least the past decade. About 23.6 million work from home either part-time or full-time, and telecommuting expands more quickly each year.

In 2001, about 3 million people across the nation began working remotely, a jump of more than 20% from 2000, according to the International Telework Assn. & Council in Maryland.

While there's no breakdown for Manhattan, most work/life consultants say that telecommuters are concentrated in the Northeast, particularly in New York City, where traffic congestion is most severe.

Just in the past year, online security has become sophisticated enough to allow workers to sign into their company intranet systems using only a secure ID and any Web browser. So employees no longer have to worry about carting a company laptop everywhere they go if they want to access office files.

While the appeal of telecommuting has been a no-brainer for employees, until recently it was a harder sell to employers. The number of companies willing to let workers telecommute, among other alternative work arrangements, has been inching up by about one percentage point a year to 30% this year, according to a national survey by Hewitt Associates L.L.C.

The events of Sept. 11 gave even the most reluctant companies no choice. According to a report issued by the New York state government on the economic impact of the attack, 563,097 employees in New York City were dislocated or disrupted, at least briefly, by the attack.

Many of them have since drifted back to the office as new headquarters have been established and buildings have reopened. There's little choice for some people, whose jobs, such as running operations in the back offices of banks or accounting firms, require an office presence.

In other cases, bosses simply prefer being able to see what their employees are up to. Davia Temin, who runs a marketing firm in Manhattan, said she trusts her staff. But if they were working from home, "I'd always be worried that they'd be sitting around e-mailing their friends and wearing fuzzy slippers," she said.

For more open-minded bosses, though, the aftermath of Sept. 11 offered proof that some employees work just as well, or better, at home.

"The best commercial for telecommuting is to throw managers into that situation to show them it can work," said Jon Van Cleve, a consultant at Hewitt who specializes in work/life issues.

Citigroup has been trying to expand, by a factor of five, its capacity for telecommuters to dial into its office systems since the World Trade Center attacks. While the office displacement is temporary, "telecommuting is growing (at Citigroup) because employees can work better, it's cheaper, and the technology is there," explained Steve Bernstein, a Citigroup executive who was given a new position just to handle continuity of office systems after Sept. 11.

Mr. Bernstein also found that the long commutes from Manhattan and Long Island to Citigroup's backup offices in New Jersey were interfering with worker productivity.

The continuing problems with congestion throughout the city may help convince other employers that telecommuting is a good idea. The Bloomberg administration may keep the single-occupant vehicle ban, which may cut down on congestion, but adds to drivers' inconvenience. And new bridge tolls are under consideration.

Mr. Ryan, who is in charge of government/industry development at American Express, said it can take him as long as two hours and 15 minutes to get to his company's offices in New Jersey-time that could be better spent on work projects.

He believes he works better at home. Despite the presence of his toddler daughter and infant son in his Upper West Side apartment, he finds he has fewer interruptions. Because he's out of sight and less accessible, he receives only the most important calls from work.

The need to telecommute also dovetailed with his personal circumstances. Last fall, Mr. Ryan's wife almost died giving birth. He had to take family medical leave to take care of his little girl and newborn son while his wife recovered. When his leave expired, he preferred to work remotely from home so he could be on hand, just in case.

Although he's gradually spending more time in the office and is scheduled to go back full-time this summer, he's now a convert. He would like to telecommute permanently, at least on Mondays.

Traffic congestion is at its heaviest on Mondays. And at home, "there's no wastage of time from people wanting to come in to your office and tell you about their wonderful weekend," he said.

Samantha Marshall is a reporter for Crain's New York Business, a sister publication of Business Insurance.