They’re a familiar sight in any airport, hotel lobby, taxi line — individuals in business suits, wielding briefcases, wheeling carry-on suitcases, clutching blackberries or cell phones. Theoretically, nearly half of them are wearing high heels, for in 2005, 43 percent of business travelers were women. The fastest growing travel segment in the nation, women business travelers have developed from a niche market into a formidable force. Defined as “baby boomers with college degrees who earn more than $75,000 per year,” they are a growing presence. But is this new generation treated differently from its pioneer feminist predecessors?

Women business travelers are apt to set out with extra burdens, not the least of which is leaving behind day-to-day responsibility for a family back home. Unlike their male counterparts who can bring different colored shirts and ties to accessorize a single business suit, women have to cram many more clothes into their carry-on bags. And, at least initially, early businesswomen confronted gender stereotypes.

“They’d look at me in the first-class cabin like some kind of oddity — ‘What are you doing here?’” said Leonore Blitz, a marketing and fundraising executive. “So I always tried to dress professionally and look the part of a businessperson even though sometimes the men were more casual.”

In many cases extra effort still is necessary. Travelers seeking upgrades learn to assert themselves, purchasing tickets with gold- and platinum-level credit cards and emphasizing their preferences.

“You have to make a point when you reserve. You don’t get upgrades unless you make it clear you want one,” said consultant Kay Koplovitz describing techniques she adopted while serving at USA Network, the first woman president of a major television network. And women have to be more diplomatic, Koplovitz conceded. They can’t get away with throwing the threats and tantrums they see some men throwing at the check-in counter.

While flight attendants on international — particularly Asian — carriers are lauded for being absolutely gracious with every flyer, the attitudes of U.S. flight attendants causes discussion. Joanna Barsh, senior partner at McKenzie & Co., expects as a matter of course that she’ll have to plead with the in-flight staff to hang up her jacket. She also described teetering in high heels on the edge of first-class seats trying to hoist a 30-pound suitcase into the overhead bin while both attendants and fellow passengers ignored her.

“Probably if I was a tall, good-looking guy, they wouldn’t give me so much grief,” Barsh lamented. “It’s bothered me for years; after all, I’m a paying customer.”

Informal counts indicate that the number of men flying first and business classes far exceeds the women, but that may be sheer economics.

“If you’re not a top executive or in your own business, you’re not going to be in the top-class cabins,” Blitz explained. “A lot of companies have cut way back.”

When it comes to lodging, some hotels have been jumping on the bandwagon to attract the growing client base, luring women with special amenities ranging from magnifying makeup mirrors and powerful hair dryers to extra skirt hangers and minibars stocked with vitamin bars and health foods. Among the quirkier amenities is a Stiletto Promotion at the James Chicago Hotel: Women in the bar receive $3 off the cost of their cocktail for every inch of high heel.

Miami’s Don Shula Hotel & Golf Club has set aside 18 women-only suites on its “Patrician Floor” stocked with breast exam shower cards and copies of PINK Magazine targeted at professional women. Guests pay a 15 percent premium for the services, and occupancy has been running at 95 percent. Marriott’s Fit For You Program allows guests to order fitness gear in their rooms so there’s no need to work out in public in the gym.

A pioneer of the working-women concept, the Wyndham Hotel group established a “Women on Their Way” program in 1995. Allied with national women’s organizations, it sponsors a program of annual awards saluting women business travelers and organizes a Women Business Travelers Advisory Board to collect feedback. The program, which has its own Web site (www.womenontheirway.com), is credited with boosting the chain’s ratio of female business guests from 19 percent when the program started to more than 50 percent last year.

Although some hotels have special programs, there still are noticeable differences. “I still see the valet for the pants, and the shoe horn and shoe shine material, but where are the pantyhose — wouldn’t it be nice to have those on hand among the minibar merchandise?” observed Rena deSisto, vice president for Bank of America.

Along with luxury hand creams and in-room ironing boards, security has been a consistent focus of hotel awareness. Desk clerks are trained not to say a guest’s room number out loud and to hand over keys surreptitiously. Hallway lighting has been increased, and frequently women are lodged near the elevators to avoid solitary walks down long corridors. Rooms with adjoining doors are not considered suitable for single women, even if the doors are securely locked.

Although some businesswomen admit a special concern about security when out of town, others are oblivious to these measures.

“I’m just focused on my work. Hotels make a big deal of this, but frankly, I don’t even notice,” said former Martha Stewart Living CEO Sharon Patrick.

And though statistics indicate 20 percent of women travelers choose a hotel for a feeling of security, slightly more than that — 23 percent — select simply on the basis of proximity to the client.

Dining presents unique challenges for women traveling alone who may be dismayed to find themselves seated at brightly lit tables in the middle of the room or, the other extreme, cached away in some dark corner. Headwaiters don’t like singles, one consultant surmised; they want the room to seem happy so they seat you out of the way. Boston public relations consultant Harron Ellenson has learned to forewarn the restaurant staff.

“When I go to the dining room, I make a point of letting the maitre d’ know I’m staying in the hotel — ‘I’m in room so and so, what’s a nice spot you have for dinner?’ — and it’s even more important when you’re eating out overseas.”

It’s no wonder that room service is the alternative of choice for 75 percent of businesswomen. An interesting courtesy: To avoid alarming guests with anonymous knocks on the door, security-conscious hotels call ahead to alert the guest that the order is on its way.

And then there’s the ambiguous matter of tipping. Stereotypically women, more fastidious and detail-oriented, are expected to weigh the service more carefully and toe the line at 10 to 15 percent. In fact, women may be inclined to overcompensate.

“I always felt I had to give a bigger tip just to prove I was a woman in business and could do my share,” admitted Ellenson.

“I tip on the high side,” agreed Koplovitz. “Just because it’s not a lot of money for me, but it is for them.”

But other factors may influence tipping habits. Blitz described an incident when she offered the maitre d’ a $20 bill to get a better table. “My colleagues from the Midwest were mortified,” she says. “I think I tip more just because I’m a New Yorker.”

When men and women travel together, male-friendly treatment is easier to discern.

“I’ll tell you when I do notice a difference,” Koplovitz said. “When I’m on a team with two guys and we go to check in, the desk clerk just assumes they are the bosses and speaks to them first — even though they are working for me. That’s still very much the case.”

“There are other times in business I notice a difference,” said cosmetics marketing executive Carole Gardner. “At work, and in conversation, there’s a difference in the words and language we use. But I don’t notice it in traveling.”

DiSisto agreed differences are more apt to crop up in the workplace: “It will be interesting on my upcoming trip to China, when I walk into the room with my male colleagues — we’ll see who gets the eye contact.”

But taken separately, gender differences are subtle.

“Of course it’s the eternal battle,” sighed Robin Duke, still glamorous and active in politics and on boards and non-profits even into her ’80s. “I’ve had problems in the past, but not too many the last 10 to 15 years. If there is an undercurrent of difference, it’s hard to pin down. You used to be an oddity — people would look at you like ‘What are you doing here?’ That’s not the case anymore.”

Even men are hard pressed to come up with examples of preferential treatment.

“The only thing that comes to mind is when a woman has a heavy suitcase. I’ll help her put it in the overhead rack. If a guy has one, he’s on his own.” said insurance attorney Frank Nicoletti.

Although travelers concede that stereotypes survive, they may not be confined to a matter of men vs. women.

“We learned this at the B School,” Barsh said. “Tall, more regal guys look more senior.”

And if that is merely human nature, at least everybody benefits.

“I can’t say I notice a discernible difference,” deSisto said. “I think people are equally nice or hostile, it just depends on personality.