A recent study has found that increased vehicle access in urban areas might actually reduce fuel consumption — as long as those cars are shared, not individually owned.

It may seem counterintuitive that putting more drivers behind the wheel could actually have an environmental benefit, but Elliot Martin and Susan Shaheen at the University of California Transportation Center say that car sharing services such as Zipcar, Car2Go and Relay Rides are actually most often used by those looking to get rid of a car.

Therefore, car sharing reduces overall vehicle ownership, takes older cars off the road and helps individuals move away from car-dependent lifestyles — all trends that reduce tailpipe emissions.

In their study of 6,281 car sharing households, the study authors found that 80 percent of those surveyed moved from owning a single car to owning zero cars after joining a car sharing service. The cars that folks got rid of tended to be more than a decade old and averaged 23 mpg. Compare that to the vehicles in a car sharing fleet, which average 33 mpg and tend to be low-tailpipe-emissions hybrids or gas-sipping compact cars.

Aside from those study participants who ditched car ownership altogether, Martin and Shaheen also found that access to a shared car often allowed households to avoid purchasing a vehicle, or a sell a rarely-used second car that took up a parking spot and cost money to keep on the road. While it’s difficult to measure cars not purchased, they estimated that each car in a shared fleet represented between nine and thirteen individually-owned cars not on the road.

“Carshare households exhibited a dramatic shift towards a carless lifestyle,” the study authors wrote. “The vehicles shed are often older, and the carsharing fleet is an average of 10 mpg more efficient than the vehicles shed.”

The authors hope that as car-sharing services increase, even those outside of high-density urban environments may be able to shed a vehicle or two.

“While this study shows that carsharing has already had a significant and measurable impact in many metropolitan regions, industry growth into new markets may produce much greater environmental benefits in the future,” they wrote.

Photo: Flickr/crschmidt