For seven years, Ken Black commuted with three other Washington workers from Columbia - a 57-mile round trip that became a mental as well a physical drain. "We had conflicts over whose turn it was to drive," Black recalled. "Often nobody talked."

Today Black, an Internal Revenue Service employe, is still commuting from Columbia. But now there are 15 riders sharing the ride, and not only are they happily talking, they are just as likely to be playing charades, munching on popsicles, or sipping sodas as they tool along Rte. 29.

What has changed Black's opinion of commuting and that of some other Washington area commuters is one of the fastest growing forms of mass transit in the nation - van pooling.

Thanks to the recurring gas shortage, the use of delivery-truck-size vans for commuting is booming, according to officials at the Department of Transportation, which has spent $52 million since 1974 to promote ride sharing.

"I think it's great," said Virginia van pooler Russell Campbell, who commutes from the Mount Vernon area to the Interior Department in downtown D.C. "It beats the hassle of driving."

In Maryland, where van pools are aided by a nonprofit, federally and state-funded corporation called Vango, there were 102 commuter vans on the road at the end of May. By June 30, 162 vehicles were running, of which 17 had Washington as their destination.

Northern Virginia van poolers have no official assistance or encouragement from state officials, but Lew Pratsch, a van pooler who works for the Department of Energy, surveyed the Shirley Highway commuter lanes for his master's thesis last fall and counted an average of 100 commuter vans a day. He estimates that today "at least 150" ride the highway into the District.

In a voice made hoarse by nonstop telephone requests for information, Lee Mahoney of the Philadelphia-based National Association of Vanpool Operators estimated a minimum of 6,000 van pools nationwide. She said the upsurge in consumer interest since the gasoline shortage began has caused more van pools to form than she can keep track of.

Maryland's Vango, often cited by transportation experts as a pioneer in van pool promotion; began operations in November 1977. The corporation matches a potential driver with riders who share a common or neighboring workplace and home.

The Baltimore-based group assists the group in leasing a van and obtaining the needed permits. Most Maryland van poolers rent their vans from Van, Inc. a leasing Rockville concern, and for a fee of $413.69 a month receive a 15-passenger vehicle, insurance and maintenance.

The van driver typically charges passengers a fraction of the monthly fee plus 12 cents a mile for gasoline and operating costs. In return for his services the driver rides free. The fare for his riders on an average 25-mile round trip based on 12 riders per van, will be $34.50 a month.

Vango surveys show that the average van carries 12.5 riders and takes nine cars off the highways, an action which van supporters say not only curbs pollution but also saves large amounts of gasoline.

Vango calculates that if the 162 vans in its fleet average 56 miles per work day, the result would be a savings of more than a million gallons of gasoline a year.

Vango director Al Duke said the leasing arrangement not only eliminates the often-prohibitive $12,000 cost of a van, but removes much of the risk as well. Insurance is provided by the leasing company and an escrow account of federal funds protects the leasing company from any van pool defaults. So far none of the Maryland van pools has defaulted.

In Virginia, financing is up to individuals. For example, two months ago, the Ted Pappas family of Manassas had to organize their own van pool of 13 Washington riders, a task that involved three family memers.

Pappas, 48, a transportation analyst for the Federal Maritime Commission and chairman of the Prince William County Mass Transportation Committee, drives the van. Ted Jr., 19, keeps the books and Melissa, 15, answers the phone, cleans the van, and sees that her dad gets up in the mornings.

Pappas charges his riders $16.50 a week, considerably less than the commercial bus rate of $20.55. He said he is having to turn away riders, although it will be years before his operation is in the black. "The theory," said Pappas, "is to end up with a paid-for van - and a free ride to work."

His Prince William County committee asked the state Department of Highways and Transportation to approve a $250,000 grant to subsidize van purchases and to establish fuel depots for the vans. The states will act on the request this fall, according to highway officials.

Washington area van poolers applauded President Carter for suggesting two years ago that the federal government buy 6,000 vans and let government workers commute in them. But the first van has yet to be purchased by the government, the van advocates complain.

Another disappointment for local van poolers is the federal government's failure to follow the lead of California where state employes are permitted to use state-owned vehicles for commuting. Federal low prohibits U.S. employees from using government vehicles for anything but official business.

This month, members of federal agencies, including HEW, Transportation, IRS and GSA, invited Vango of Maryland to help set up employe van pools. Vango's Duke said the agencies have come to the right place.

He'd like nothing better than to start with the federal workers at 1600 Pennsylvania Avenue.

"I could survey the White House [for potential van pools] next week..." he said, "and we could have the vans on the road in a week." CAPTION: Picture, Ted Pappas of Manassas financed and organized his van pool of 13 riders. By Gerald Martineau - The Washington Post