Billy Packer almost put a Willie Nelson song on his telephone's answering machine last week. The song is titled, "On the Road Again."

For the better part of a typical year, the 42-year-old Packer lives in relative tranquility in Advance, N.C., where he runs a successful real estate business and gets worked up mostly over cable-TV boxing matches. Come winter, though, his year-round "hobby" of college basketball becomes his daily bread.

And he will be especially busy the next few weeks, as most of the game's best teams hurtle toward the NCAA tournament's final four April 2. CBS Sports, which two years ago had neither a college basketball contract nor Billy Packer as its color commentator, will be there.

Packer, who, at season's end, will have analyzed two dozen games for CBS and 18 ACC contests for Raycom Productions, paused briefly in Washington this week to win a half-serious three-point "shootout" with Maryland Coach Lefty Driesell. At a pregame breakfast, in the same amiably precise tone he uses in the booth with CBS' Gary Bender, Packer previewed his intinerary.

"I'm here today, tomorrow I go to Atlanta for two ACC tournament games Friday (tonight)," he said, as his wife Barbara looked on patiently. "Friday night I fly to New York to do some stuff for an NCAA show on CBS; Saturday I'm going to see the Big East final, just to goof off.

"Saturday night I fly to Kansas City, do the Big Eight final Sunday, the Pairings show Sunday night, back to New York for some business Monday, to Syracuse Monday afternoon to speak . . ." He paused to breathe as Barbara Packer raised her eyes and smiled. "Tuesday back to Washington to do a show with Jim Simpson (of ESPN), Tuesday night back to Winston-Salem to get some fresh clothes . . ."

You get the idea. Besides the television, Packer also finds time and place to do a five-day-a-week college basketball wrapup for Mutual radio. He does it with Al McGuire, who for six years was his off-the-wall booth partner at NBC, which lost Packer and the NCAA's final four to CBS after the 1980-81 season.

"We do it wherever we can," Packer said of the two-minute radio show, for which he prepares questions and McGuire, unrehearsed, fashions answers. "A couple of weeks ago we had to tape it in a men's room at O'Hare Airport in Chicago."

While TV exposure is blamed in some quarters for helping spawn such "corruption" as the three-point basket and the shot clock, or what some fear is a television-financed imbalance among the NCAA's 274 Division I teams, Packer believes otherwise.

"Television has done more for college basketball than any other single sports entity," said Packer, an all-ACC guard at Wake Forest in 1960-62. "It has made it a national sport of what was primarily a regional sport, it's gotten kids in rural areas involved in a game which had primarily been a big-city sport. And the more you open up the game, I think, the better it is."

Which explains why Packer likes the three-point shot. "In a game that's become so much an inside, passing game, in an era of the great leapers, it gives kids who don't have the ability or size to go inside a chance to contribute," he said.

And why he doesn't agree with Indiana Coach Bobby Knight's recently expressed wish that the NCAA create a separate class for, say, 50 Division I "superpowers."

"Every time you start to limit things, after you start setting numbers, what's to keep somebody from saying, 'Well, 50 is too many, we really need only 45,' " Packer said. "I'm for opening up the NCAA tournament, let all 274 teams take a shot. What does it hurt for an Indiana State, or a Fullerton State, or a Georgetown, just a few years back, to get in there and try to do their program some good?

"You don't want to legislate the game down to where you have to be 6-5 to play," he said. "That's what the pros have done, and they've backed themselves into a corner. It's gotten to where only the truly gifted can contribute, and it all looks the same."

ABC's three regional telecasts of the United States Football League's debut Sunday drew a national Neilsen rating of 14.2, nearly three times the rating the network expects to get on a typical USFL Sunday. ABC isn't rushing to revise its expectations, a spokesman said yesterday, since the rating obviously reflects, among other things, fans' initial curiosity over Herschel Walker's pro debut for the New Jersey Generals against the Los Angeles Express. Walker was seen in 72 percent of the country last Sunday; he'll be seen in 100 percent Sunday, as ABC goes with a national telecast of the Generals at Philadelphia.