THE MOST MEMORABLE television commercials are usually those with taglines that become part of the culture - "I can't believe I ate the whole thing!" and "Where's the beef?" leap to mind as prominent examples.

But in Utah a locally produced series of TV ads has had just as much impact . . . without so much as a single spoken word on the soundtrack.The "Don't Waste Utah" anti-littering campaign from the Utah Department of Transportation (with some help from Fotheringham Public Relations) has become a real favorite. It has also been quite effective.

You've seen the spots, of course, which feature a "Mad Max" motif - a tall, good-looking Mel Gibson type wearing a three-day stubble, a black leather jacket and boots, driving a grungy old Malibu with his faithful dog at his side as they travel through scenic southern Utah roads. The twist, of course, is his attitude toward litter - and litterers.

This week marks the second anniversary of the ad campaign, and a new commercial, the fifth in the series, hit the airwaves for the first time on Monday. "You'll see these spots from now through November," says Kim Morris, community relations director for UDOT. "It's the longest we've ever been able to have them on the air."

In 1989 the $150,000 budget for the anti-litter campaign went primarily toward filming the first three spots. But with just one additional ad filmed last year and another for 1991, more of the annual budget can pay for prime commercial air time.

Morris cites a pair of Dan Jones polls that show 53 percent of Utahns recognized the campaign in 1989 and 78 percent in 1990. This is helped enormously by the actor who plays the "Max" role, James Andrews, who dons the character's garb and drives the signature car to schools weekly, speaking to assemblies of students about the evils of littering.

But the most pleasing aspect, Morris says, is that littering along the highways has noticeably decreased. "We rely on our maintenance people who have worked the highway day after day for years, and to a man they tell me the campaign has reduced litter - some say 40 percent."

Bruce Jensen, who created the campaign with Fotheringham colleague Randy Stroman, adds that "the Adopt-a-Highway program, where community groups take a section of the highway and clean it up a couple of times a year, was doing well, but this raised the visibility to such a degree that they've really gone gangbusters."

Morris said several proposals from ad agencies in town were considered, but none had the appeal of Jensen and Stroman's. "There was a country-western motif, one that revolved around the slogan `Stuff It' and Utah Jazz players, one that crossed `Oscar the Grouch' and `Rambo' with the character popping out of a garbage can, and there were some straightforward, traditional ones.

"This was the most aggressive and unusual. It had strong visuals, good music, quality production - and in their proposal they were talking about using 35mm film. One of my biases against agency public service announcements is the lack of quality."

So how did Jensen and Stroman come up with this "Mad Max" scenario? "As we thought about the problem - people littering - it became apparent that an appeal from Woodsy Owl wouldn't do the trick," Jensen said. "We had to make it kind of cool. That led to the idea of an anti-hero, someone who was not going to litter, someone that kids could see as an interesting character. So we hit on `Max,' somebody who was a neat guy, who was cool but not preachy. There's not a word of dialogue in the first four spots. We just let the action speak for itself."

A local director, Tom "T.C." Christensen, was hired, Andrews got the "Max" role after some 50 local actors auditioned, his companion Hoover is a search-and-rescue dog and the car was, more or less, created for the ads. Jensen said, "We wanted kind of a mean street machine. And we started thinking about a '68 GTO or something like that. Then, looking through the want ads, we found a '69 Chevy Malibu. It was pretty, kind of baby blue, powder blue, white top, nice interior and had 93,000 miles on it.

"We took it out to a mechanic and said, `OK, we need you to rip the bumpers off, rip the vinyl off the top, we want a real gritty texture. He repainted it and mixed in sand and hair with the paint to give it a real gritty texture, and then put on the new bumpers and wide tires and lamps on top and the grille in front.'

"People have fun with the campaign and the spots have an attractive woman, a hunky guy, a dog, a muscley car - there's something for everybody."