Zipcar, Inc. announced the launch of its fourth annual Low-Car Diet challenge.  As part of the challenge, Zipcar is calling for car owners in participating markets to pledge to give up their personally-owned vehicles for 30 days and seek alternative methods of transportation, starting July 25, 2011.

Participating markets in this year's Low-Car Diet challenge include Atlanta, Baltimore, Boston, Chicago, New York, Philadelphia, Pittsburgh, Portland, San Francisco, Seattle, Toronto, Vancouver and Washington, D.C. To apply for participation, individuals can visit: http://zipcar.com/lowcardiet.  

Once all applications are received, three participants per city will be selected and will form "teams" to represent their respective market. These participants will be equipped with Zipcar memberships and prize packages to make the Low-Car Diet challenge exciting, rewarding and convenient.  Starting on July 25, for 30 days, participants will walk, bike, take public transit or use Zipcar to get where they need to go, leaving their personally owned vehicles parked in their driveways or garages.

Teams will chronicle their experiences with weekly video blog posts and regular social media updates. At the end of the challenge, Zipcar representatives will compile the videos taken and additional results from each team and will post the videos to Zipcar's Low-Car Diet website. Friends, family, fans and other Zipsters can visit the site and vote on the team that best embodies the Low-Car Diet lifestyle. The team that receives the

Last year, participants reported that they increased their miles biked by 80 percent, decreased miles driven by 69 percent and lost a total of 247 pounds. The 262 Low-Car Diet participants across 12 cities also reported that they walked a total of 5,400 miles; took 1,667 bike trips and 4,168 public transit trips throughout the duration of the challenge.