CIVIC DUTY; Saving the world, one convenient car-share at a time.(News)(car sharing services)

Byline: JEFF SABATINI

Kathy Summers wants to know why AutoWeek is interested in car sharing, perhaps for good reason.

The marketing chief for Chicago's I-GO car-sharing service is suspicious because our interest appears a bit incongruous: We love cars and we own cars. In contrast, Summers' nonprofit group would love for you to turn in your own keys and grab a set of theirs, perhaps to a Honda Civic, which is what I-GO offers. Just toss the keys back for the next person.

At least 20,000 Americans now participate in car cooperatives or car-sharing programs, mostly in big cities like Boston, Los Angeles, New York, Philadelphia, San Francisco, Seattle and Washington, D.C., where population density and access to public transportation make the programs feasible.

Think of car-sharing programs, both non- and for-profit, as short-term rental with members paying to use a car for as little as an hour. Members make reservations via phone or online, in advance or spur of the moment. Shared cars are parked near a train, subway or bus stop. The member gets a car, uses it for whatever time they need wheels, and returns it to an assigned place. Fees include an hourly rate plus mileage ($3 to $8/hour and 50 cents/mile), with gas, insurance and maintenance usually part of the fee. The member-per-car ratio is typically 15 to 30 members per car to insure both high use and ready access.

While many car sharers do not own a car, a significant number use a shared car as a second car. Business use is the ...