Car-sharing service Zipcar is challenging automobile owners nationwide to participate in its third annual Low-Car Diet. Beginning Sept. 14, participants in Zipcar cities – including Atlanta – will pledge to personally give up their vehicles for 30-days and find other ways to meet their transportation needs. Participants will be given a Zipcar membership and other incentives designed to make their experience convenient, fun and rewarding.

The Zipcar Low-Car Diet includes the economic, environmental and health benefits associated with a smart lifestyle. Last year’s 252 Low-Car Diet participants demonstrated that a minimal car regimen was easier than cutting carbs; 61 percent of the 2009 participants said they planned to go “car-free” after the 30-day challenge. Additionally, participants increased their miles biked by 132 percent, decreased their miles driven by 66 percent and lost a total of 413 pounds.

More Americans today are getting smart about alternative modes of transportation, finding that walking and biking save time, money and the environment. According to a recent survey, conducted by the Pedestrian and Bicycle Information Center, the number of reported walking trips more than doubled since the first survey taken in 1994, from 18 billion to 42.5 billion in 2009. Bicycling trips saw a similar increase, from 1.7 billion to four billion during the same period.

Those who rise to the challenge will share their car-free experiences using Twitter and other social media channels. Individuals who are interested in participating in this year’s Low-Car Diet in the United States or Canada, should visit http://bit.ly/lowcardiet to fill out an entry form.