Americans love their cars. More than 213 million vehicles clog the nation's freeways, city streets and rural byways. But a hi-tech scheme in San Francisco aims to persuade drivers to give up their beloved vehicles, writes Maggie Shiels.

Why own a car when you can share one? That's the approach taken by San Francisco City Car Share, a non-profit organisation which aims to reduce the number of vehicles in the city.

Drivers log payment details with electronic fobs

"We want to make car sharing more hip, more fun and more sexy than owning a car," says Kate White, co-founder and deputy director of City Car Share. "This programme is a real, viable and convenient alternative to owning a car."

The scheme aims to ease city congestion, parking hassles and environmental abuse by giving current car owners a reason to give up their vehicles while still being able to drive when they need to.

It works along fairly simple lines. Members pay a $300 refundable deposit and a $10 monthly fee to join. For $2.50 an hour and 45c a mile, they can drive a new VW Beetle, four-door family car or station wagon based at one of 11 locations around San Francisco. Insurance and petrol is included in the price.

Beat the jams

At an orientation meeting in the company's downtown office, 10 new members are shown how to make reservations online.

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City Car Share's Annie Bourden then hands out electronic key fobs that beep members into the car when they reserve it. Down at one of the pods, as the garages are known, Annie shows the new recruits how to use the fob.

"Can everyone see the red light flashing on the side of the door?" she asks. "Just hold your key fob in front of it. The door will spring open when it recognises your fob number.

"If you're early, your fob information which is stored on a system behind you will not have been sent to the car's onboard computer and it won't recognise your fob when you walk up to the door."

'Talk' to each car

The garages are fitted with black boxes that communicate with each car's onboard computer through a shortwave radio, says deputy director Kate White. "Each day we download data to the black box's modem telling it who has reserved the car and for how long."

When the car is returned, the modem picks up the shortwave signal and logs the time and the distance driven. That is then sent back to the company's database where it's used to tally up a member's bill at the end of the month.

Kate White says shortwave radio proved to be the cheapest and most reliable means to track the cars. "Cellular didn't always work at many of the garages, some of which are underground."

The scheme itself is proving popular. In the past six months, 850 people have signed up to use the 30 cars based in San Francisco. Next month, the project expands to Oakland and Berkeley.

Elizabeth Sullivan, the first person to join City Car Share, says she got rid of her own car in order to save money.

"I looked at my expenses when I owned a car and it was $400 to $500 a month. Now my car share expenses add up to $100 to $150 a month."

Kate White: It's "hip" to share cars

New member Catherine Harris says the scheme tallies with her beliefs. "I am very interested in plans to make urban places environmentally more sustainable. I love cities and I have always been an environmental activist and being able to put those two things together is an incredible gift."

The company gets 1,200 reservations a month, and organisers say Berkeley University is researching just what impact the project is having on overall car use. If successful, Kate White says the federal government may consider extending the scheme to other parts of the country.

Henry Ford, the man popularised the petrol-powered motor car, will no doubt be turning in his grave.