The Yellow Pages for the District of Columbia has a 29-page section of listings for moving companies -- well over 200 companies to choose from.

One of them is a 38-year-old Washington-based, family-owned company that is offering its customers a pioneer pricing and service concept for moving a houseful of one's possessions.

In contrast to the rest of the household moving goods industry, Interstate Van Lines computes moving charges on the basis of how much space the family's possessions take up in the moving van, not on how much they weigh.

The insides of all Interstate trucks are marked off into units of 400 cubic feet and quarter-units of 100 cubic feet each. The shipper's charge is based largely -- entirely in some cases -- on how many units are filled and how far the shipment is going. Interstate offers three levels of service with different elements in each -- from luxury, which includes maid and limousine service, to more bare-bones plans -- but the common thread is the unusual volume-pricing concept.

"The shipper can stand in the truck and see exactly how much space their furnishings take," says Arthur E. Morrissette, president and founder of the company. He was standing in one of his vans in front of a house in Burke, Va., pointing to the truck's inside markings. "So there's no question in their mind what their charge is. You've heard of weight-bumping," he said, referring to an illegal practice of adding to the weight of a truck after it has left the consumer's home but before it is weighed for charge assessment. "This eliminates that entirely; people pay by the space occupied."

The company, headquartered in Springfield, is doing some other things that appear to make it out of the ordinary:

It will pay a family $3 to visit its headquarters and see its "talking house," a fully furnished model house located in its warehouse used for training employes in moving techniques. The idea is to have the employes "learn their jobs . . . and chip and knick things here and not out on the job," according to John N. King, director of marketing.

"If you told people you were going to tour a warehouse, they'd think you were at the depth of your social calendar, but we want to erase a perception that has been presented by the moving industry."

Monthly, the firm conducts a free two-hour packing class to instruct on the correct way of packing belongings to avoid damage when moving.

It tries hard to motivate its employes with a program that includes routine evaluations that give top scorers the top jobs with increased financial benefits -- 45 percent to 80 percent more in hourly salaries, doubled road expense allowances and paid hotel expenses on moves -- and a close-in reserved parking space at headquarters marked clearly for the "sales consultant of the month."

It is training its employes continually. A mandatory hour-long meeting every morning is used to instruct employes over and over again on how to pack and how to treat customers. Employes are required to appear all together at the door of the family moving; one of them recites a set speech promising "top hat service." Then an Interstate doormat is laid down -- a door mat employes are instructed to wipe their feet on when they come in the door.

To take a look at how Interstate's new system works in practice, The Washington Post followed the move of one area couple and found that they, at least, were well-satisfied.

Al and Lorraine Gunther, who moved this month from Burke to Nanuet, N.Y., found that Interstate had underestimated the amount of space in the van their possessions would take, but well within the 10 percent guideline considered in the industry to be a reasonable estimate.

Al Gunther said he believed the underestimating was unintentional and attributed it to "the newness" of volume estimating. "I think the truck was as well-packed as it could be packed," he said. "Looking at the truck and watching them unpack, there were no holes on the truck, believe me."

The Gunthers had opted for Interstate and its middle plan, partly to try the volume concept -- the move was their fourth since 1972 -- and partly for the control it offered them. "What was very important to us was the arrival date," Al Gunther explained while Interstate employes moved their furniture out into the truck. The Gunthers wanted the move to take no more than a week. "I have a limited time off, so timing is the most important aspect of this move . . . and they guaranteed delivery within that time," he said.

Packing began on a Friday afternoon -- a half-day early with the Gunther's approval -- and was completed on Monday. The truck was loaded Monday and part of Tuesday. Delivery in New York began Thursday and was finished on Friday. The beds were loaded on the truck Tuesday and unloaded Thursday, letting the Gunthers and their two boys sleep in their own beds all but two nights. "They even brought a TV set and chairs for us to use while they were packing ours," Lorraine Gunther said.

The Gunthers said they were impressed by Interstate employes' promptness, courteousness, thoroughness and care with their belongings, both loading and unloading. "They put me at ease. I'm a nervous wreck when it comes to packing," Lorraine Gunther said. "When you're moving, everything you've got is on that truck."

Very little was broken, Lorraine Gunther reported by phone -- some minor things and a leg on an antique clothes tree. Interstate personnel already had told them they would replace the items, something promised when the Gunthers had paid extra for full-replacement value insurance.

Two pieces of legislation signed into law last year gave the household moving goods industry new pricing and operating freedom. The trucking deregulation act made entry to the industry easier, restricted the companies' collective rate-setting powers and granted companies pricing flexibility. Another bill affecting only the moving industry is designed to make sure the consumer has better information in selecting moving companies, allows more flexibility in offering different price and service options -- like binding estimates -- and establishes procedures for the settlement of shippers' disputes with moving companies.

Interstate had asked for and received Interstate Commerce Commission approval to begin to try out its plan just before the new laws were signed. The approved three-tier plan, contained in a 30-page, relatively easy-to-read tariff compared with the inch-plus thick documents of other companies, works like this:

Under the most complete moving plan, the total charge for a family move is based solely on a single charge for each of the spacing units occupied, depending on the mileage the goods are being taken. This plan is not cheap. The cost is likely to be almost 55 percent more than Interstate's least expensive plan.

"There are no extras," the company advertises. Even loading or unloading on the weekends is included. The plan offers a written guarantee on the specific dates for loading and the exact (the company's emphasis) date for delivery. If the company fails to live up to the dates, the shipper's bill is reduced by 25 percent for each day of delay. In other words, four days late means a free move.

The middle plan, at a different rate per unit, includes virtually all the packing, labor, and containers that might be used in a move, but excludes the maid, courtesy-car, travel planning and similar services of the higher-price plan. Failure of the company to pick up and deliver within the agreed contract dates entitles the shipper to reimbursement of 10 percent for each day of delay. This plan is about 25 percent less costly than the luxury plan and 25 percent more clostly than Interstate's least expensive move.

The third plan, which still represents more than three-quarters of Interstate's business, is more like the service offered by most movers but also uses a rate for each unit occupied on the van. However, it also requires additional charges for such things as packing services and containers. The price does include some things a lot of other companies count separately like moving appliances or pianos, carrying things up stairs or on elevators. The company doesn't agree to reimburse the shipper for failure to perform on the contract service dates.

Because each of the company's vans is marked on the interior to indicate the units of space on which the charges are based, there is no guesswork involved in the price to be paid at the destination once the van has been loaded. The customer is shown the line marking the starting unit before loading begins and the unit-marking line when loading is finished. As a result, the customer knows when the shipment leaves the house exactly what the transportation cost will be without waiting to be advised of the exact weight of the shipment.

Not everyone is thrilled with the concept. An article in the latest Consumer Reports, published by the nonprofit Consumers Union, warned consumers to be wary of volume pricing. "It is all too easy for a mover to make a shipment take up more space in the van than it has to, so that the bill is higher," it said. However, two industry observers who were involved in last year's trucking reform legislative efforts suggested that two important considerations militate against "volume bumping." For one thing, a mover cannot spread things too loosely in a van since things bouncing around cause damage that movers do not want; the other is that the customer is standing around watching and will be able to see if there are gaps, they said.

Consumer Reports also noted that Interstate Van Lines, a household goods carrier, tecnically solicits its moving business under its freight-forwarder authority, a distinction that could allow it to bypass consumer protections that carriers must provide. Interstate's Morrissette said they began to offer their volume-pricing service under the freight-forwarder company so that if it didn't do well, it would have less of an impact on the overall operation. It was a business decision one ICC official confirmed made sense when starting off with "a rather innovative service." Morrissette also insists that Interstate offers consumer protections "far in excess of what's required by the regulations."

Although the Interstate Commerce Commission couldn't provide complaint data immediately, data provided by the Better Business Bureau of Greater Washington indicated that Interstate's record is good. A spokesman said that only one complaint had been filed against Interstate by someone dissatisfied with its service in the last three years. Although the bureau doesn't draw any conclusions and won't compare one firm with another, the spokesman acknowledged that some firms generate one complaint every month.

Morrissette, whose company has annual sales of $21 million a year, says he hopes to increase the number of the two top plans he sells, which now represent about 22 percent of the company's moves.

"Most of the time people in business try to get more business by reducing price," he said. "We don't. We are emphasizing service. We want to increase our prices because then we can buy better labor so we can better perform for our customers.