Laura Gault, a Fairfax, Va., commuter, thought she was seeing things one morning on her drive to work. An 8-foot-tall tomato rolled past, and a truck driver waved hello from his window. "It was bizarre,' recalls Gault. "I remember seeing the words "Salad Singles,' and I think the tomato was stuffed with tuna or chicken salad.'

That was the sort of reaction Richard Kent was hoping for. The brilliantly colored, billboard-like ad on his company's tractor-trailers could herald a new trend in outdoor advertising.

Kent is president of the Orval Kent Food Company, a Wheeling, Ill., firm that supplies delicatessens in major cities with bulk containers of 100 varieties of ready-made salads, including potato, pasta and chicken. Served from deli bins, the salads appear to have been made on the premises.

A couple of years ago, Kent wanted to improve awareness of the first product bearing the firm name. Packaged in single-serving containers, Orval Kent Salad Singles were distributed to supermarkets in 11 cities. But like many new products without big budget marketing support, they usually were not on shoppers' grocery lists.

Kent's solution came from an unexpected source: the printing company that had embellished his trucks with the company logo. Modagrafics, of Rolling Meadows, Ill., sent him a report on an American Trucking Associations survey showing that 10.1 million people see the average tractor-trailer in a year. And 91 percent of survey respondents said they notice trucks displaying words or pictures.

In fact, he thought, why not a whole side of a truck? "Since we had limited ad dollars to spend, we had to do something different to get attention.'

Working with a 3M process that would make a giant photographic-quality billboard possible, Modagrafics produced king-size silk screens from a color photographic ad created by the Orval Kent Company's ad agency and printed them on adhesive-backed vinyl sheets. It also sent application teams to the company's distribution centers to turn mundane tractor-trailers into 9-foot-high by 48-foot-long mobile billboards.

That is how Laura Gault came to be surprised by a giant tomato.

Most of the Orval Kent Company's ad space is leased. Modografics scouts target markets for trucking companies that are willing to lease the sides of plain-sided tractor-trailers. The trucks may be hauling anything from light bulbs to pantyhose. Orval Kent offers trucking firms $1,200 for the right to advertise on 25 vehicles for three years.

Including the printing and application costs of the decals and the leasing fees, Richard Kent estimates his company pays 21 cents for every 1,000 people who see its ads.

"People who live in markets where our product isn't yet distributed have called to say they have seen our trucks passing through, and they want to know where they can get Salad Singles,' says Kent.

Does motorists' craning of necks threaten to cause highway pile-ups? The Transportation Department apparently does not think so. Bureau of Motor Carrier Safety rules allow full-scale ads on a truck as long as they do not interfere with its exterior lights, are not obscene and do not create an optical illusion--such as stripes or circles making the truck seem smaller.

Other companies also are profiting from spiels on wheels. James Foley, president of New York-based Prestige Panels, Inc., is giving people in New York, Chicago, Detroit and Washington something to gawk at.

Foley wanted to offer advertisers more outdoor attention in cities like New York and Washington. "That's where advertisers want to be--where the eyeballs are,' he says.

In February, 1985, Prestige Panels started rolling out 10-foot-high by 22-foot-long panels for specially designed flatbed trucks. Foley, mum about the leasing cost of one of his mobile billboards, says he gets a lot of repeat business.

Woman's Day, which frequently leases the company's panels in New York to attract advertisers, has been a client from the start. Three days after the magazine's first panel made its Manhattan rounds, Foley received a phone call from a Woman's Day ad representative.

"He said, "This is terrific!'' recalls Foley. "He said the magazine had never gotten that much response from ad agencies and advertisers.'

That is king-sized advertising on a roll.

---