The automobile has long been revered as an emblem of freedom and prosperity in Germany. Drivers are so attached to their cars as a primal badge of identity that lawmakers do not dare to set speed limits on autobahns, where cruising speeds often reach 130 mph.

But the price of maintaining this cherished icon keeps rising every year. Not only do Germans pay some of the highest fuel prices in the world at close to $5 a gallon, they are grumbling more than ever about traffic congestion, accidents and air pollution.

So this port city's bold effort to reduce car use represents nothing less than a revolution in the German psyche. For the past nine years, Bremen has been encouraging its 550,000 inhabitants to abandon car ownership by supplementing an ultra-modern public transport system with a car-sharing scheme that allows citizens to rent a vehicle quickly at relatively low cost.

Cars can be rented at 37 city locations, and may be picked up for a quick shopping trip or a weekend excursion. Cities elsewhere in Germany and Europe are considering similar experiments.

"I drive less than 2,000 kilometers [1,242 miles] a year, so it doesn't make sense for me to own my own car, with all the cleaning, maintenance and fuel costs," said Hans Dinger, who runs a picture-framing shop. "Car sharing is also a special way to say you care about your environment, and I want my son to appreciate the earth as much as I do."

Bremen officials say it is hard to pin down the impact of the program, but they believe the combination of car sharing, bicycle use and public transport has enabled one-third of Bremen's households to dispense with their automobiles. While car ownership is still growing fast in the suburbs and elsewhere in Germany, Bremen has reduced daily traffic circulation in the canal-lined, cobblestoned streets of the inner city by about 500 cars per year.

Michael Glotz-Richter, a Greens party senator who helped launch the program in 1990, said the popular success of the car-sharing plan is rooted in the flexibility of having access to a car without the expense and hassle of owning one. "At first, people felt they were making a sacrifice to help the environment. But now they are breaking their dependency on a private car because they see how easy, convenient and cost-efficient this kind of program can be," he said.

For about $40, a Bremen resident buys a smart card that allows a driver to make reservations and gain access to the vehicles located around the city. They have their choice of 10 car models, from subcompacts to vans. The cars recognize the smart card through a transponder field on the windshield that opens the doors. Upon returning the car, a swipe of the smart card across the windshield locks the door and transmits journey data that is used for monthly billing.

For example, a three-hour shopping trip covering six miles runs about $7, while a two-day, 120-mile weekend excursion costs about $85--rates considerably cheaper than those charged by car rental agencies. The city program covers all other costs, such as wear and tear, depreciation, tax, insurance, gasoline and cleaning.

"I think the most positive factor is the convenience," said Peter Emmrich, administrator of a public health center. "Once you realize that you don't need a car as part of your identity, you gain a lot of freedom. It's like renting a video. You just order a car, use it and then turn it back in."

If the program seemed like a strange novelty at its inception, it has now become a mainstream habit. "I got rid of my car a year ago after I moved to an apartment in a central location," said Klaus Stavenhagen, a city government employee. "It used to be a status symbol but the disadvantages of a car have become too great. Who needs one if you just use it to pick up groceries?"

Detlev Teichman, a local marketing researcher, said he is not ready to surrender his Volkswagen because it remains an essential part of his family routine. Even so, he welcomes the car-sharing program as a helpful adjunct to his lifestyle.

"When my wife is using our family car, I can always order up a second one that is suitable for any occasion, from a compact car to a large van," he said. "The variety of vehicles is really something of a luxury. When the sun shines, you can go for a convertible."

Although Bremen has a tradition of environmentally friendly urban experimentation, Glotz-Richter said similar German car-sharing programs could replace as many 1.2 million cars.

Other countries that have launched or expect to embark on car-sharing programs include Switzerland, Austria, Denmark, Luxembourg and the Netherlands. Glotz-Richter was recently invited to speak at a conference at the Massachusetts Institute of Technology about lessons learned from Bremen's experience, with the idea they might be replicated in Boston and other U.S. cities.

A European Union study showed that if applied on a continental scale, such programs could reduce car mileage by as much as 20 billion miles a year, which in turn would curtail carbon monoxide emissions, which are thought to contribute to global warming, by as much as 5 million tons a year.

Not surprisingly, the program has been scrutinized by Europe's leading car makers, including DaimlerChrysler, which is Bremen's largest employer. But rather than worry about losing customers, Glotz-Richter said the manufacturers seem eager to cooperate because they, too, believe car sharing may represent the wave of the future.

Indeed, the enthusiasm for car-free lifestyles is proving infectious. With the financial support of Bremen's city government, apartment complexes now offer substantial discounts on monthly rents if tenants pledge not to own a car. That idea has spread to other cities, including Hamburg, Cologne and Freiburg, where the environmentalist Greens party has gained substantial public support for eco-friendly policies.

"It's a great feeling of liberation when you get rid of your habitual dependency on the automobile," said Pit Klasen, a Bremen architect who swore off owning an automobile six years ago and now designs car-free neighborhoods. "But it only works when you know you have the flexibility of getting into a car when you really need it. That's where car-sharing comes in."

During a tour of his apartment complex, Klasen showed the dramatic change in landscape as well as lifestyle that occurred once he and his neighbors gave up their cars. Vacant parking lots are used as playgrounds and an underground garage serves as a communal recreation room, with space left over for a self-sustaining laundromat that uses rain water collected from the roof.

"It's true that Germans have always had a special love affair with the car," Klasen said. "But there's no reason you have to remain trapped in a bad and unhealthy relationship."

CAPTION: A pedestrian zone in Bremen's old city center bustles with activity. Officials there estimate that a third of the residents have given up their cars.

CAPTION: Michael Glotz-Richter, a Greens senator, shows a model of downtown Bremen. He helped start a car-sharing program in 1990.