It is 8:30 a.m., rush hour on M Street. The lanes are clogged with taxis, cars, trucks, buses, limousines and Martha Sanders, who is pushing a grocery cart full of moldy food and empty soda bottles eastbound in a westbound one-way street.

Sanders, 64, a gray-haired woman in a tattered green coat, knows exactly where she is going: to a supermarket trash bin to get more food.

In the afternoons, she trudges to Lafayette Park for empty soda bottles, to another trash bin for more food or to an art museum for culture. At night, she sleepts on a mat inside Luther Place Memorial Church at Thomas Circle.

"When I'm not finding money or getting food I feel like I'm wasting minutes," she says as the blocks a honking garbage truck and lifts her cart's front wheels out of a pothole. "That's my employment."

For most of her life, Sanders worked as a switchboard operator. But after age 44, she lost a number of jobs because of her temper. By the time she was 51, in 1965, she was permanently unemployed.

Since then, she has been steering a full grocery cart in Washington traffice every day. She is part of local lore, a point of reference among residents. Commonly known as "the woman with the grocery cart," she has frustrated motorists, amused tourists and bewildered traffice policemen.

"Martha is as familar in Washington as its monuments,' said the Rev. John F. Steinbruck of Luther Place Church. "She is Washington's only moving monument."

Sanders' search for food keeps her from feeling useless. It also serves a physical need: she eats some food from the cart. And she gives some to other homeless women who sleep at the church. But she distributes only the top layer.

She keeps about two feet of food -- dripping, moldy tomatoes, yogurt, cottage cheese, cucumbers and liver -- in her cart at all times.

The full cart reassures her she will not go hungry. But even the rotten, inedible food is valuable to her. She owns nothing else.

"I bring everything with me so people don't take it all away," she says, as though describing property of great worth. "Some of the hostesses [at the church] tried to take some of my bread last week. But I told them I spent too many hours getting it."

Martha Sanders never married, although she says she was in love three times and engaged once. She still wears the engagement ring, a silver band with a disc full of tiny crushed diamonds that do not sparkle. It was given to her when she was 26 by a man named Jeff who pumped gas in a service station.

Sanders broke the engagement because she decided she was in love with someone else. Jeff told her to keep the ring in case she changed her mind.

"I used to like to date lots of fellas," she says. "You have more fun that way. When you start getting serious you have to make up your mind about which one. I couldn't."

Sanders grew up in South Carolina, the daughter of a traveling salesman. She graduated from high school during the Depression and then took jobs as a theater cashier, a social columnist for a small newspaper in South Carolina and an operator for the telephone company.

When she was about 30, she moved to Bethesda to work as a switchboard operator for the National Naval Medical Center. Ten years later, she worried that other operators were "telling tales" about her.

She could not adjust to working as a switchboard operator elsewhere. Each of her next half-dozen jobs lasted about six months. One lasted two days.

The problem: Sanders would get angry whenever coworkers or supervisors would laugh or speak loudly or do anything else to disrupt her concentration. It was as though they had stepped over a fence into her private back yard. She would yell at them. They would exchange looks. She would yell some more. And she would get fired.

"Once i told a supervisor to lower her voice and she said to me, 'Who do you think you are, talking to me like that?'" Sanders said. "The next day I was called into the personnel office. That was it."

Between 1958 and 1965 Sanders was spending part of each year working, the other part unemployed, fired for losing her temper.

She decided to "have fun" supplementing her unemployment checks by riding a bicycle through Bethesda and Washington, picking empty soda bottles from the streets and riding them to supermarkets, where she would trade them for a few cents.

The hobby became an obsession.She was so busy collecting bottles that she did not have time to go to supermarkets. She'd pile her bottles in her tiny Bethesda apartment, forming deep stacks on counters and floors. When she ran out of room, she dumped her new bottles in her brother's backyard.

"She left us hundreds of bottles, heaps and heaps of them in the back," said her niece, who declined to be identified. "My brother and I took them to three or four grocery stores and we made $15 each."

By 1965, Sanders had no more job prospects. She stopped receiving uncemployment checks. She lived for a year with her brother and his family, until she punched her sister-in-law in the nose and her brother called the police.

"My mother walked into our basement in the room where Martha had her things," said Sanders' niece. "Martha got mad and punched her real hard. I guess Martha thought my mother was in her territory."

Sanders moved to Washington. She began searching for food as well as bottles. And she went from riding a bicycle to pushing a grocery cart.

She lived in seedy hotels until two years ago, when her rent rose to $130 a month and she could not find enough money or bottles to pay it. She has lived on the streets and at Luther Place Church ever since.

"I prefer to have an apartment but I was so set to not spending the little money I had," she says.

She does not receive Social Security because she thinks she will get more money if she waits until she is 65. She says she does not receive welfare payments because there are too many forms and too many social workers and she is too busy collecting food and bottles.

On a typical morning, Sanders pushes her shopping cart to a trash bin behind a supermarket at 21st and L streets NW. She stands on a milk box and pokes her head though the opening of the six-foot-high bin.

"These vegetables will make a good soup," she says as she tosses mushy tomatoes from the bin into a box on the ground.

Then, she examines each piece of food she has thrown into the box, like a jeweler studying diamonds for flaws.

"This tomato has a rotten spot," she says, tossing it back into the bin. "So does this cucumber."

Sanders feels that the men and women who work in the supermarket leave food in the trash bin to be kind to her. She reciprocates by flattening the empty boxes scattered around the bin and piling them up neatly.

She is serene these days, given to losing her temper only when other street people try to steal food from her grocery cart.

"I try to make myself as happy as possible because worry and thinking like a pessimist, you kill yourself."

As she trudges her cart along the double yellow line of K Street, from the trash bin to Lafayette Park, cars honk at her. She ignores them, walking at her own pace, forcing them to dart around her.

"If people think they are more elite or high class because I take around this big cart, it's not true," she says. "It's like Shakespeare said. "The world is a stage on which each of us plays our part.'"