Shortly before he left on a trip to Europe last fall, Irving R. Wechsler of Chevy Chase, Md., heard about the Travel Information Center at Philadelphia's Moss Rehabilitation Hospital. Weshsler called called and quickly had what he wanted: the lowdown about getting around Paris, Rome and other areas of Italy if you're handicapped.

Wechsler has had no use of his legs since he contracted polio as a young man, but it hasn't stopped him from taking occasional trips, which he did as a government employe and which he still does in retirement. Wechsler spent two weeks in Paris and five in Italy and upon returning wrote a letter of thanks to Susan Couch, the librarian who runs Moss' travel center.

The material he got, he wrote, "was particularly valuable and accurate, especially about the need to be stubbornly persistent in dealing with the Louvre staff. They do lie and pretend ignorance; if one presses, and reaches the public relations staff, they are very helpful." In Italy, he added, "the facilities are woefully limited, but all Italians seem determined to be helpful."

His specifics on travel for the handicapped ended up in a file at the Moss travel center. "We ask the people we help for feedback," says Couch, "and a lot of the time we can use that information to help somebody else."

Moss will provide access guides to many large cities and airports, information on cruises and accessible cruise ships, tourist attractions, hotels and motels, and travel by car, train, bus or plane.

Attached to a rehabilitation hospital, a travel center for the handicapped seems quite natural, yet the one at Moss is thought to be the only one of its kind and anwers queries from throughout the United States and abroad. "If we don't have the information, we'll tell people where to get it if it exists," says Couch.

What the center is doing reflects what the handicapped are up to: They are traveling more, and because of that they are finding more places accessible to them. Appropriately, this is the U.N.-sponsored Year of Disabled Persons. Still, this does not mean th at things have changed dramatically for the better.

"The badly handicapped are in trouble when they travel," said Wechsler. "But there's really nothing to keep them from trying it. You have to take chances and concentrate on what you are seeing, not the problems you encounter."

One group lobbying for the handicapped who travel is the Society for the Advancement of Travel for the Handicapped, a New York-based group headed by Murray Vidokler. The nonprofit organization is made up of more than 200 travel agents and tour operators whose main goal is to educate the travel business to the needs of the handicapped.

"Within the industry things are getting better," said Vidokler. "Charity no, service yes; that's what we say. But we've accomplished about a tenth of a percent of what we have to accomplish."

There are 30 million Americans with some form of handicap, Vidokler says -- "a big market." It is not just the physically disabled.

Several airlines -- United and American to name two -- now have reservation and information services for those with hearing or speech impairments. To communicate, they work with the same device many have been using to talk to friends and relatives -- obsolete printers like the old Western Union machines.

For the learning disabled or mentally handicapped, travel has traditionally been with their families. One of the few, perhaps the only agency set up exclusively to provide travel opportunities for them, is a Philadelphia-based group called the Guided Tour, founded seven years ago by a social worker named Irv ("Please, not Irving") Segal.

The Guided Tour has run trips to New York, Washington, the Poconos, Williamsburg, Nashville, Nassau, California and Mexico, to mention a few. There is generally one social worker or special education teacher for every five clients. The clients come to the Guided Tour from service agencies or from their own families. But Segal draws the line at parents or relatives accompanying the retarded person.

"We want them to learn to be independent," said Segal, who has been working with the retarded since 1965. "Travel is a growth-producing experience. We're not just travel for travel's sake, but travel as it fits into life."

The travel groups consist of about 25 to 30 people, and in places like Disneyworld, the higher-functioning handicapped are sometimes permitted to take off on their own and meet later at a designated point. This, says Segal, not only gives them the opportunity to feel free and independent, but permits the staff to pay closer attention to the lower-functioning clients who need more guidance and help.

If you are handicapped, the information available about travel seems limited only by the facilities that are accessible. If they exist, somebody has probably written a brochure or guide about them.

There is even a guide to gudes, called the International Directory of Access Guides, published by Rehabilitation International USA, an agency that sponsors programs to assist the disabled. The disabled or elderly can get a free copy by writing Access Guide Directory, Rehabilitation International USA, 20 W. 40th St., New York, N.Y.

To contact the travel center at Moss Rehabilitation Center, you can call (215) 329-5715. Moss also has a TTY number (Teletype terminal), (215) 329-4342. In addition, there is something called "Rehab Line," a pretaped phone message system offering information related to rehabilitation and disability. Rehav Line operates during the day, Monday through Firday. Phone (215) 329-0838.

You can request information by mail by writing Moss at 12th Street and Tabor Road, Philadelphia, Pa., 19141. Moss also has a brochure listing the taped messages on the Rehab Line.

For information about the Guided Tour, write 555 Ashbourne Rd., Elkins Park 19117. Or phone (215) 782-1370 or(215) 635-1960.

Among the tour operators for the handicapped are Flying Wheels, Box 382, 143 W. Bridge St., Owatonna, Minn., and Helping Hand Tours, 175 Fifth Ave., New York, N.Y. 10010. Helping Hand runs tours in cooperation with Amtrak, which recently allocated $2.8 million to provide barrier-free access to trains at 18 stations in the nation.

Another good source of access guides in the United States is the National Easter Seal Society Information Center, 2023 W. Ogden Ave., Chicago, Ill., 60612.