Sure, it’s hot on the ground but it’s hell at 40,000 feet for many business travelers this summer, who say that flights crowded with vacationers make it nearly impossible to get any work done let alone relax a little.

The ongoing bouts of airline fare wars and the nation’s robust economy have sparked a boom in travel this summer and that means business travelers cannot expect to have an empty seat nearby to park a briefcase or laptop.

“The crowds have been building ever since the airlines were deregulated, and this summer, the crowds and the families are heavier than I’ve ever seen,” said Bob Landerman, vice president of sales for L.A. Gear and a frequent traveler.

This has caused havoc for business travelers from the packed airports to the long lines at gates to the often-overbooked planes to the airsick babies and, finally, to the long waits at the car rental desk.

“I stopped trying to work during travel about two years ago,” said John Hathaway-Bates, president of the The Business Forum, a Los Angeles-based firm devoted to bringing business leaders face-to-face for troubleshooting sessions. “If you plan to accomplish something on a plane and then end up sitting next to a child or old age pensioner and are not able to, which is very often the case, the stress can be terrible.”

It was not yet 7 a.m. one day last week at Los Angeles International Airport, as the crisply suited Hathaway-Bates, a native of Oxford, England, sat reading the Wall Street Journal.

Awaiting the same flight to San Francisco was a mostly shorts-and-shirts contingent of travelers. Children scampered about, babies were crying and couples anguished about the vacation items they had left at home.

“I know a lot of people who don’t care to travel on business anymore,” Hathaway-Bates said.

But many business travelers don’t have the luxury of staying home.

The number of passengers flying out of LAX rose from 45 million in 1987 to just under 58 million last year with much of that increase reflecting a rise in business travel.

In a recent survey of 500 business travelers, 55 percent of the respondents said they are on the road and in the air more than they were five years ago.

Load factors, the percentage of seats filled on a given flight, are running close to 75 percent this summer, several percentage points higher than normal.

Even on non-summer months and with fewer children on board, business travelers find flights more crowded and with less of a productive work environment, according to the survey by New York-based Roper Starch Worldwide Inc. for Hyatt Hotels Corp.

Some travelers say they have tried to find ways to cut down on travel but it’s not always easy.

“For a lot of business, there’s no way getting around being there, so you’ve got to travel,” said Joe Dickerson, president of the Niles, Ill.-based Dickerson Engineering Inc., who was in Los Angeles last week on business.

Jeani Lund, a Los Angeles-based travel promotions manager for Bloomingdale’s, is one businesswoman who has chosen to travel less these days.

Employed in the travel industry for 25 years, Lund took a new job a few months ago in part because she wanted to be out-of-town less than 35 weeks a year.

“People on vacation want to drink and chat while business people want to get something done,” Lund said. “The problem is airlines don’t make attempts to tend these differing needs.”

Lund and other business fliers propose having certain flights allocated just for them an idea quickly rejected by United Airlines spokeswoman Mary Jo Holland.

“We would never really limit who can and can’t fly on a plane,” Holland said. “It wouldn’t be cost effective, and you can bet there would be all kinds of people saying ‘the business flight should be the 11 o’clock flight instead of the 9 o’clock flight.'”

Holland said the airline does offer what it calls the “Premier Section” in the economy class, where business travelers who rack up at least 25,000 miles a year can sit together in a front area of the cabin.

Time was, according Hathaway-Bates and other veteran business travelers, that one could avoid the crowds even in summer by catching an extra early morning flight.

“A decade ago or less, it wasn’t a great problem to find a flight with a seat between you and the next fellow,” he said. “That’s just not possible now, no matter when you fly.”

Indeed, veteran business travelers say upgrading to the business class or other premium service is the only solution to the summertime travel blues.

“I’ve gotten used to the game of gathering (frequent flier) points and getting upgraded,” said Ellen Bluestone-Reilly, a travel promotions agent for Universal Studios Hollywood. “There’s just no room to work in coach.”

But even that’s not foolproof when you have an 8-year-old sitting next to you.