An Indiana couple with two grown children has been chosen by the state's second largest trucking company, C.R. England and Sons, Inc., to drive the company's showpiece vehicle and be goodwill ambassadors for a year.

Don and Delores Unsell, both 47, from LaPaz, Ind., near South Bend, will take turns driving a new Kenworth T600A tractor truck costing more than $130,000 and filled with electronic gear and the latest amenities.

The two said they will travel 175,000 to 200,000 miles during the next year promoting safety and projecting a positive image for truckers.

Unsell learned to drive a truck when he was in the U.S. Air Force from 1960 to 1964. His wife was trained by C.R. England earlier this year in Salt Lake City.

They said they will each drive five hours at a time while the other rests, driving 20 hours out of each 24 hours on their coast-to-coast trips.

Unsell said he and his wife will live in the truck's sleeper compartment when they aren't driving _ a 5-by-8-foot, air-conditioned, padded compartment behind the truck cab that is big enough to stand up in and equipped with double bunklike twin beds and a television set.

Delores Unsell said she plans to put flowers in the compartment and pictures on the padded walls. "It will be homey," she said. The two expect to be home in Indiana about two or three days a month. About once a week, they said, they will spend a night in a motel. The rest of the time they will be on the road, visiting the company's customers, visiting new territory and carrying payloads across the nation.

Among the items the Unsells will carry behind their 444-horsepower truck will be trailers filled with frozen fruits and vegetables, machinery, chemicals and hazardous materials, sporting goods, industrial supplies and appliances.

Both Unsells expect the next year will be an adventure, even a second honeymoon, they said, smiling. They won't generally know their next destination until they arrive at a warehouse, company or store with their truckload of goods. Then they will be told where to pick up their next load and where to take it.

Unsell said most Americans don't appreciate that practically everything they eat, wear, use and enjoy is brought to them by trucks. "Even things that are shipped by rail and airplane are most always sent on to their final destination by trucks," he said.