For Rosetta Womack, who is 81 and carries a cane when she walks, 10 blocks is a long distance to travel to buy groceries.

Sometimes she goes by bus, sometimes by taxi. When she has finished her shopping , she asks one of the men who wait outside the Georgia Avenue supermarket to drive her home and bring her groceries indoors. They provided what amounts to a gypsy, or unlicensed, cab service. She pays them what she can afford - usually, she says $1.65 or $2.

"Now I make out the best I can because I have arthritis and heart trouble," she said during an interview a few days ago. "It's difficult and it's costly also."

In her grocery shopping difficultiles, Mrs. Womack is not alone.

As the number of major chain supermarkets in the District of Columbia had dwindled over the years, thousands of city residents have found the distances from their homes to their food markets increasing. Researchers who have studied the issue say that the severest difficulties confront those who are elderly, handicapped or poor - especially those who do not cars.

Almost no section of the city has been left untouched by what has been a nationwide trend: the flight of major supermarkets from central cities to the suburbs because of shifts in shopping habits, increased reliance on automobiles, the changing economics of the supermarket business, the urban riots of the 1960s, crime and other factors.

For many city dwellers, the decline of the neighbourhood supermarket has required considerble accommodation and some ingenuity. In neighbourhoods such as Mrs. Womack's, some shoppers rely on gypsy cabs or other informal car-for-hire arrangements. Others form monthly car pools to go where the biggest supermarkets have gone - the suburbs. Some shop at downtown supermarkets because they can get there by bus without a transfer - a reflection of the commuter orientation of Washinton's bus system. Some, who must walk long distances to supermarkets take their children along to push their shopping carts home and act as lookouts against possible theft or vandalism. Some simply make fewer shopping trips.

For Mrs Womack, a lively assertive woman who declined to be photograph and who lives on a retirement annuity from her nearly 35 years as a post Office employe, the days of going around the corner to an eighbourhood Safeway store are only a memory, as they are for many other Washington residents.

Safeway, the city's dominant food chain, once had a small store on Georgia Avenue south of Columbia Road, about a block from Mrs Womack's Harvard Street home. She remembers shopping there during the 1930s. Safeway vacated the shop, along with a number of its other stores, after the 1968 riots here.

Long before her neighbourhood Safeway closed, however, Mrs Womack had apparently stopped buying groceries there. Why she stopped is not altogether clear. Her recollections, she said, are hazy. But one reason apparently was that the small Safeway had only a limited assortment of groceries. "They just didn't have what you wanted," she recalled.

To get to other larger Safeways farther north along Georgia Avenue, Mrs. Womack would rely on her grandchildren and a variety of improvised shopping carts. "I would take either the baby carriage or the boy's cart and one of them would go along to pull it," she said. For a time, she walked to the supermarket, accompanied by her grandchildren. As she grew older, shebegan to ride there and abck by bus. Her grandchildren would meet her at the supermarket with a cart and haul the groceries home.

Now the nearest Safeway is even farther north, at Georgia Avenue and Randolph Street NW. Two other less distant Safeways have closed, one of them on Georgia Avenue near Newton Place and the other on New Hampshire Avenue off Georgia Avenue. For Mrs. Womack, a widow who still lives at the brick row house on Harvard Street that her family moved into in 1922, the trip to the supermarket has become slightly longer, increasingly difficult and considerably more costly.

When she feels well enough, she rides a bus up Georgia Avenue to the Safeway, paying a 20-cent face, a reduced rate for the elderly. Occasionally, she is given a free lift to the Safeway by a driver for a senior citizens' center she visits. Otherwise, she goes to the supermarket by cab - a trip for which she apparently is regularly charged an illegally high fare.

Mrs. Womack insisted that taxi drivers always demand $1.65 for the ride - an amount that city and taxicab company officials describe as improper. The fare, they said, should be $1.10, the one-zone rate, because her trip does not take her across Randolph Street, the dividing line between taxi zones.

To get home with her groceries, Mrs Womack depends on the informal car-for-hire system that operates outside the supermarket. She said it is always available.

On a recent afternoon, one such driver was shuttling shoppers to their homes in his station wagon. Asked who his main customers were, he replied, "It's mostly older people." Mrs. Womack said she gives the drivers $1.65 or $2 for a ride because she feels they should get at least what licensed taxi drivers demand and because they also carry her groceries inside to her dining-room table. They do not charges a fare, She added "You give them a donation."

The once-simpler chore of going grocery shopping has in recent years prompted considerable research and urban debate here and across the United States.

In one D.C. government study, many low-income, elderly and handicapped persons living in Southeast Washington communities cast of the Anacostia River were found to do their principal shopping for groceries and other household necessities either by riding a bus to a downtown store or traveling to a commercial area in Prince George's County, such as the Eastover Shopping Center. For such persons, the study concluded, available transportation was "most inadequate."

The report , published in 1976, found that low-income families without automobiles made half as many major shopping trips as those who owned cars. The elderly, it said, faced similar obstacles. "A typical shopping trip by an elderly per son usually requires riding the bus to a desired location with a return trip by taxi. Such procedure is usually nnecessary, despite the cost because of the burden of carrying packages any distance on the return trip. Thus, the elderly make fewer shopping trips."

Transportation officials who took part in the study said in interviews that Southeast Washington residents shopped in the suburbs or downtown for a variety oif reasons in addition to the dearth ofsupermarkets wherethey lived

Most direct bus service, they noted, leads downtown or to the suburbs. Much of Anacostia and surrounding communities is hilly - a deterrent to going shopping on foot. Many residents, they said, believe - correctly or not - that suburban supermarkets offer lower prices, higher quality and more variety. Many elderly persons avoid walking to a supermarket because they are afraid they may be robbed."The element of fear is a lot greater than you may realize," J.W.Lanum, a city transportation official who took part in the study, said, "Young kids are really doing a number on old folks these days."

A survey by the Washington Urban League of low-income residents of Northwest Washington's Shaw and Adams-Morgan neighbourhoods also pointed to widespread concern about difficulties in going grocery shopping. The Urban League study, published in 1976, found that 69 percent of those who responded to its survey did not own cars, 41 percent lived more than four blocks from the nearest supermarket and 45 percent took 15 minutes or longer to get there.

Elsewhere in the United States, a number of studies had also underscored the problems low-income families face in doing their grocery shopping. Though their findings differ, sometimes markedly, most such studies appear to show that many poor persons travel considerable distances by buses, taxis, car pools and other arrangements to supermarkets where they believe the prices are lower and merchandise is better.

"This notion of lack of mobility - that's not true," Clyde Smith, an associate professor of marketing at Morgan State University in Baltimore, said in a telephone interview, Smith conducted a study of grocery shopping ptterns among inner-city residents in Oakland, Calif., in 1974. "There are many alternatives," he added," "and they use them."

Part of the national debate on this issue centers on the extent to which low-income families travel to major chain supermarkets or are confined, instead, to shopping at higher-priced mom-and-pop grocery stores and other independent markets closer to where they live.