Florence Shaffer, 74, of Falls Church, paid for her taxicab ride with coupons on Monday, as did more than 30 elderly Arlington residents, unofficially launching the first publicly subsidized taxi and van service of its kind on the East Coast.

Shaffer's four-mile, $4.70 round trip to a grocery store, and the Arlington residents' trips to a senior center, were paid for by the city and county under a one-year experimental "Fare Wheels" program.

Officially announced yesterday at a press conference by Arlington and Falls Church officials, Fare Wheels was created, with a $156,000 federal planning grant, as a model of how communities can end expensive and duplicative transportation programs.

A study last year by the Northern Virginia Planning District Commission, which helped create Fare Wheels, found that almost 50 local public and semipublic agencies in Northern Virginia were operating nearly 200 buses, vans and cars for needy residents. Commission officials criticized that as "chaotic, inefficient and expensive."

Under the Falls Church Fare Wheels program, residents without access to an automobile and who have limited income -- $27,000 for a family of four -- are eligible to receive $20-a-month in coupons.

They can use the coupons to hire any of more than a dozen participating taxi and van firms to go anywhere at any time, "even to visit Aunt Matilda in Washington," said Claudia Passen, city director of housing and human services.

About 1,000 of Falls Church's 9,500 residents meet the income requirements, Passen said, but probably fewer than 500 also meet the "transportation-impaired" test, which means that they lack access to a car.

As of yesterday, only 24 persons had applied for Fare Wheels identity cards and coupons.

Falls Church has been spending $9,000 a year to hire vans from two nonprofit groups to drive needy city residents around.

Passen said they were available only on certain days, followed limited routes and usually required reservations 24 hours in advance.

In Arlington, eligibility for Fare Wheels has been initially limited to the elderly and handicapped already receiving help from the county -- about 100 residents.

The kinds of trips and destinations also have been limited initially, said county coordinator Dottie Dake.

But county board chairman Ellen Bozman said yesterday the program will be expanded.

Falls Church Mayor Carol DeLong said "We really don't know how many residents are transportation needy . . . including those temporarily unable to drive." But, he said, Fare Wheels will provide greatly expanded transportation service for all needy city residents.

The $156,000 grant that created Fare Wheels is the last in a seven-year federal program which officials of the Urban Mass Tranit Administration (UMTA) yesterday called "one of the most successful projects we've ever done."

More than 120 communities have started somewhat similar programs, although only San Diego has a program exactly like Fare Wheels.