Call of the open road. A growing number of Americans are enjoying a wayfaring life on wheels

FROM 43 states and Canada they came for friendship ... through jazzercize, square dancing, seminars on fly-fishing - and listening to Eddie Baxter at the Lowrey Electronic Keyboard. They parked 800 Silver Streaks, Prowlers, Airstreams, and Nomads cheek by jowl in the mammoth parking lot of Pasadena City College. The expensive rigs - including a $265,000 Newell the size of a Greyhound bus, a $240,000 Beaver complete with radar dish - had bumper stickers that read: ``Grandma and granddad's playground,'' or ``We spent our children's inheritance for this.''

For a burgeoning segment of mostly older Americans, ``this'' increasingly represents a new way of traveling, recreating, meeting old friends, and making new ones all at the same time. Recreational vehicles (RVs) - for years a symbol of the new, mobile America - hit hard times during the recessions of 1973 and '79 as gas prices soared and RV sales slumped. Now, the itinerant life on wheels, where friends meet via the citizens' band radio or in one of the country's 16,000 RV trailer parks, is back on a roll.

``RVs have added new dimensions to travel for everyone from young families to retirees - the freedom to travel together, cheaply and without restrictions,'' says Beverly Edwards, a spokeswoman for the Good Sam Club, the world's largest RV club. ``Many choose to become full-time RVers and sink temporary roots wherever the sun shines.''

The number of RV parks is still growing, up a few thousand from five years ago. But the number of ``households'' owning RVs is up even more dramatically - by millions, to 7.5 million at last count, representing 10 percent of all American homes. Projections by the Recreational Vehicle Industry Association in Washington indicate that 20 percent of Americans would like to own an RV.

``The American public has an almost fanatical attachment to the outdoors that goes back to our heritage in freedom and individual rights,'' says Dave Humphries, president of the RV association. ``Old and young have increasingly realized it's not only the best way to experience the outdoors for extended periods, it's the least expensive and most versatile [way].''

On this particular day in late December, all RV roads led to Pasadena for a celebration of sorts. The Good Sam Club was holding its annual International Rose Parade get-together (know as a ``Samboree'') and celebrating its 20th anniversary and a membership that has doubled in a decade to 500,000-plus. There were four days of activities and seminars, and the Rose Parade to boot. But the primary reason these RVers travel cross country is to gain a new sense of community.

``I became an RVer to get out of the house and meet people,'' says Mimi Starbuck, a longtime member from Rialto, Calif. ``I love the out-of-doors and I love people, and you don't get either when you stick yourself in a hotel.''

``It's an easy form of life to see the country, to really get out in it,'' says her husband, Dale. ``People say, `Aren't those expensive to drive, don't they waste energy?' - but when you think how much heat and lights you're not using at home, it comes out much cheaper.''

Breakfast and dinner were the best times to see the RVers in action - firing up propane grills, playing cards, and chatting about rig designs or previous Samborees.

``The first thing I do after parking our rig is search out our old friends,'' says Lucille Wheeler, from Upland, Calif. ``The second thing I do is seek out new friends.''

A retired sheriff says he's met so many people while putting 30,000 miles a year on his 32-foot trailer that he now mails 750 Christmas cards each December.

What, besides chasing down friends, is there to do at a Samboree? There are seminars: ``Citizen Band Radios: Theory and Practice''; ``Highway Safety and Your RV''; ``Ifs, Ands, and Buts of RV Refrigerators.'' At one lecture, a representative of the Thetford Corporation was ``taking the confusion out of chemical additives, with special attention to RV holding tank problems.''

And at night there is entertainment. In Pasadena, Broadway revues were offered, and ragtime by that erstwhile ivory-tickler of Lawrence Welk days, Joanna Castle. Not to mention tours of nearby local attractions - Disneyland, Universal Studios, museums, and parks.

The club is not all fun and games. The ``Sam'' in Good Sam is short for Samaritan, and members do much to advance the cause of RVing. In so doing they live up to the club logo, a smiling man with a halo.

``We've always tried to clean up the image of the RVer by admonishing him not to empty his sewage where it will [harm] others, not disturb other campers with generators and lights, and to be a good citizen on the road,'' says Dale Starbuck, a longtime member. ``Unfortunately not every RVer does the same.''

For starters, Good Sam has an eight-point membership pledge: ``I will stop and give aid to fellow campers.... I will pull off the road whenever I am causing a slowdown.... I will leave my campsite in better condition than when I found it....'' Good Sam also sponsors a national effort for retarded Americans in the special Olympics, and gives $80,000 a year to Dogs for the Deaf.

This was one of three yearly national-international Samborees. But each state has regional and local clubs that sponsor their own Samborees year-round. Emory and Elizabeth Folk joined the local chapter in Susquehanna, Pa., and visited yearly gatherings with such themes as Mardi Gras, and the Wild West. ``We even had one Christmas in July,'' says Elizabeth, ``complete with Christmas lights on every rig. It's too cold ... [in] winter for an RV Christmas in Pennsylvania.''

Other RV clubs abound. The Family Motor Coach Association has 35,000 members. The Wally Byam Caravan Club, a club made up of Airstream owners, sponsors caravans of its special aluminum-covered trailers. And President Reagan made a special trip to Bowling Green, Ky., in the summer of 1985 to address 15,000 members of the National Campers and Hikers Association. ``RVers are a good, wholesome group,'' he told the gathering.

Some Good Sammers do nothing but visit their own club's gatherings. The Folks joined Good Sam in 1971 after they saw a magazine ad that reprinted the club's eightfold pledge. But they didn't retire until last year. Then they were on the road for 49 weeks. ``We only returned home to Pennsylvania to fill out our taxes, then we were off again,'' says Emory Folk.

Their destinations included state Samborees in Maine, Pennsylvania, Maryland, Illinois, and Florida. Later in the year, they joined 20 other couples who rented RVs and toured New Zealand. Everywhere they went, they collected sew-on patches to display on their Good Sam vests and compare with friends.

They also compare rigs, though RVers are not a chauvinistic lot. ``Once we park, we're all part of the same cloth,'' says John Weaver, who pulled his 14-year-old Excella 500 Airstream next to a new $250,000 motor home. ``When I bought this baby, it was the answer to RVing. Now they've got 'em five times this size.''

The insides of some RVs might startle the unitiated. Many now include color TV, washer and dryer, stand-up showers, built-in vacuums, and skylights. Not to mention sound systems that can be heard in the next county. But neither size nor amenity is the point. Just as often you see a pop-up trailer or van bed with an air mattress. ``What we sacrifice in size, we make up for in mobility,'' one VW owner says.

Are there drawbacks to the RV life? ``I used to think there were two: confined quarters and limited wardrobe,'' said one 15-year veteran. ``Now I find when I return home, I walk myself to exhaustion in my kitchen and bedroom. You and I, we don't need so much space.''