WHEN Charles Kuralt goes "On the Road," Charles Kuralt goes on the road. That familiar Quaker-Oatsy voice at the other end of the phone announces that Kuralt is calling from a telephone booth inside a Piggly Wiggly store in Sheboygan, Wis.

Charles Kuralt will go anywhere to get the stories no other reporter wants.

"I try to avoid anything that's relevant or significant or newsworthy," he says.

This is a TV newsman talking? Indeed, one of the best, and one of a kind. Kuralt has been studio-bound for a while now, concentrating his pudgy energies on "Sunday Morning," the weekly 90-minute CBS News program that has won so many awards that they'll have to start making up new ones just to keep honoring it. And for the past 16 years, off and on, Kuralt's "On the Road" pieces have been regular, therapeutic morale boosters for battered viewers of the "CBS Evening News." Now Kuralt has a spiffy new van and a shiny new time slot, leading off prime-time Tuesday nights for 10 weeks this summer with a half-hour "On the Road" to be followed by "Our Times with Bill Moyers." Both shows get special premiere outings tonight, immediately following "60 Minutes," at 8 and 8:30 on Channel 9.

Naturally there is speculation that once the summer run is over, if the ratings are okay, "On the Road" might make it onto the regular CBS prime-time schedule. But Kuralt says, "I just hope we do 10 good shows. I don't think this will lead to anything, myself. I'm sure CBS has a wishful hope; after all, if it did continue, it would be a very inexpensive half-hour to produce.

"Bill Moyers is the one really hoping to continue. This is what he's always wanted, a prime-time program. I really don't expect it myself. My memory of these summer news ventures is that they are just that."

To judge from the first two programs, the pattern for "On the Road" will be one strong piece plus two nice ones on each show. On the first program, the strong piece comes in the middle of the program, when Kuralt talks with some of the men who, 50 years ago, risked their lives for $11 a day to work on the construction of the Golden Gate Bridge. Some men died, some were injured, most felt lucky to get the job.

Clearly the high point of the second show, airing Tuesday night at 8 on Channel 9, has Kuralt in Buffalo, S.C., for a visit with Agatha Burgess, widow, solid citizen and maker of corn muffins. She spends all day, every day, cooking meals for hungry people who live in her community. She tells Kuralt, who constitutes a portly obstacle for her as she paddles around her kitchen, that what she always wanted was to be somebody who "lived by the side of the road" and was considered "a friend to man."

Agatha Burgess has realized her life's ambitions.

Clearly, Kuralt's is not the kind of show likely to end up at the other end of a furious litigant's fiery demand for outtakes (although--of course--in these nutty times, you never know). Kuralt chortles, "Maybe that's why CBS News president Van Gordon Sauter approved it so fast, 'cause he knows there's not a lawsuit in it." It's all good news, really, but in Kuralt's hands, it does not come off innocuous or patronizing. He tells you things you're glad to have heard, and takes you places you are pleased to have been. Television should do more of that.

"I haven't a doubt that some of my colleagues find it kind of sappy," Kuralt says of his folksy journalism. "I don't. The stories are true and about people who really live in the country. You learn that the country isn't in flames; I think it's nice to be reminded of that."

"On the Road" doesn't look at the overexposed "dark side of the American dream." It looks at the bright side that still exists, although Kuralt notes,

"I don't think the show has a message, except maybe an implied message--that many people live at peace with their neighbors and help one another along, and that there's a good deal of justice and humanity in the country despite what we read and hear in the news.

"I've never made the claim that it's something television needs," Kuralt says. "It's just a nice way for me to make a living. It's been an extremely pleasurable experience. As a reporter, you're always asking argumentative questions and always going where you're not wanted. I don't have to do any of that. This is a very pleasant change. If I run into people out here that I don't like, I just don't do a story on them."

Kuralt is such an important fixture at CBS News that it was startling to hear, earlier this year, that he was considering an offer from Metromedia to anchor a new national nightly newscast starting this fall. Kuralt says he thought of taking the job only for an instant, and only because the money being offered was "three or four times as much as I am making at CBS."

That means Metromedia must have been offering him around $1.5 million a year, and probably a five-year contract with juicy benefits built in. Kuralt went to Boston to talk to Metromedia executives but ended up turning them down the same day. He does not regret it. Sources at CBS News say Kuralt has an attractive new contract there, and that it was he who forced CBS to drop its original plan for the summer schedule--one that would have combined the Kuralt and Moyers shows into a single broadcast, with Kuralt playing second fiddle to Moyers. Kuralt, graciously enough, says the Moyers show is "the more important" of the two.

For a while, Kuralt was also making speeches and writing articles that seemed critical of then-new CBS News president Sauter and the jazz-hot style he imposed on the organization. "When I got kicked off the morning news, I was a little irritated, and I made that speech," he says, referring to the brief period when he was daily as well as Sunday morning anchor for the program. "I thought they were going to speed up the 'Morning News' to the point that it wouldn't be a news show at all. But I sort of got over my irritation quickly, especially when I realized I didn't have to get up in the middle of the night and do the broadcast any more. I really don't want to 'anchor' anything. It's so much more fun being in Sheboygan, and I'm not kidding."

Kuralt says that whatever his initial reaction to Sauter, he now thinks "The CBS Evening News with Dan Rather" is no glitzerama but instead "a sturdier and better program than ever."

There's no question Kuralt has thrown himself into his new program. He really does drive the van himself from time to time. And he wrote the lyrics for the title tune: "I have miles and miles ahead of me, tales to listen to, time to spend/ Up ahead, the road is bending; wonder what's around the bend." Good song, fine show.