Some people consider driving a car enjoyable; others look at it as a necessary evil. Either way, it’s a big expense, and one that’s growing all the time between the initial purchase cost, maintenance, insurance and rising gas prices. In urban centers, there’s also the cost of parking, which can be hundreds of dollars a month.

But for most people, a car is a must. After all, every once in awhile, you need a car to get around even if you can do much of your travel on public transportation. It’s not very cost-effective to rent a car every time you need to go to the grocery store or want to go out of town for the weekend.

That’s where car sharing comes in so handy.

Car sharing, a concept that’s been around in the U.S. since the late ’90s, is gaining in popularity in major cities where it’s expensive to own a car or traffic is bad enough to make people rethink their transportation options. According to the Car Sharing Network (, just under three dozen cities in the U.S. and Canada currently offer some form of car sharing to at least some degree; Boston has the largest network with about 4,200 members sharing 131 vehicles.

How it works
The basic concept is that individuals or businesses pay a membership fee to join, and some combination of a flat rate per hour, a per-mile fee or both. Vehicles are parked in strategic, convenient locations around the city and reserved ahead of time (usually last minute). The car-sharing company or organization pays for the car, gas, maintenance, repairs, insurance, parking and cleaning.

Typically, people who want to car share need a driver’s license and a credit card. They also have to be over 21. Costs vary significantly by company and metro area. For instance, City CarShare in San Francisco charges a $30 application fee, a $300 refundable damage deposit and a $10 monthly administrative fee. Using a car costs $4 an hour during peak hours between 10 a.m. and 10 p.m., and $2 an hour in off-peak hours, plus 44 cents a mile.

With Zipcar in Boston, sign-up costs include a $25 application fee, a $100 refundable membership deposit and a $50 annual fee for the “occasional driver” plan. When you reserve a car, it costs $8.50 an hour or $65 for 24 hours. All reservations include 120 free miles, with 20 cents a mile after that.

Most individual members of Seattle-based Flexcar tend to reserve a vehicle for 2 ? to three hours and wind up driving a total of about seven miles going to the grocery store or to doctor’s appointments, said president and CEO Lance Ayrault. In the evenings, they use the cars for entertainment; on the weekends, it’s day trips. During weekdays, the cars are most often used by businesses for sales calls.

‘Neatniks’ only, please
Those who think car sharing means they can trash the cars should think again. Your mom is less strict with her car than these guys.

“No smoking and no pets, please,” Ayrault said. “This is a little different than car rental. People in general think if they’re in a rental car, they can do whatever they want. With car sharing, people tend to use same vehicles over and over, so there’s a lower incidence of abuse. We ask people to maintain the car as well. Walk around the car once and make sure there are no dents or dings. Every week we come out, clean the cars, and make sure that if there is a dent, we find out who did it. The insurance has a $1,000 deductible; you’re responsible for first $500.”

People who use car sharing tend to often make significant changes in how they get around, according to a university study. The University of California Berkeley study, funded by the Federal Highway Administration, found that 30 percent of San Francisco’s City CarShare members sold one or more of their own cars and 67 percent opted not to buy an additional car. Members’ use of cars dropped 47 percent, while their use of public transit, walking and cycling increased. Collectively, the members saved 720 gallons of gasoline a day.

Philly hops on board
Philadelphia is the first major city in North America to start municipal car sharing for city employees, said Robert Fox, director of administration for the city’s Office of Fleet Management.

“We’re trying to reduce dependency on vehicles,” said Fox. “We have better places to put the money.”

The city started car sharing in April 2004 because it was faced with a budget deficit; departments were told by the managing director to “think outside the box,” Fox said. They went with car sharing and cut 300 vehicles from its fleet of 6,000. They expect to sell off another 200 cars.

It’s helped the fleet department make better use of a dwindling parts and repair budget at a time when fuel costs are skyrocketing, Fox said.

“We’re not saving money as much as avoiding deficits,” he said.

Adoption has been a struggle, Fox said, because vehicles have traditionally been considered an entitlement that went with certain jobs, whether the cars were used regularly or not. Gains have been made in smaller departments, such as procurement and personnel, but other departments have dug in their heels. Fox said his office will be just as adamant about switching to car sharing.

“Departments and individuals believe the car comes with the job,” he said. “In a city as old as Philadelphia and as entrenched in its ways, the culture has to be changed. It’s been a lot of fun. Some people not thrilled with us, but you don’t get to do this in government very much. We’ve changed the culture.”