Founded in 2006, BlablaCar is a European car-sharing website with over 1.6 million members in France, Spain, and the UK.  The site connects drivers with empty seats and paying passengers -- with the objective to reduce cost and carbon emissions for all involved.  And above all, the site encourages social "blabla" fixtures such as profiles and ratings to assure a trustworthy ride-sharing community.

The average car occupancy rate in Europe is 1.2 persons / car, which is inefficient, not very environmentally friendly, and simply expensive.  BlablaCar estimates that average car ownership costs in Europe exceed 5,500 euros per year.

BlablaCar's average car occupancy rate has increased to 2.7 persons / car, and depending on how frequently a driver uses the site, he or she can easily offset over half of car-owner costs by "renting" out his or her car seats.

Moreover, with every added passenger, a driver will greatly reduce his or her carbon footprint!  Check out this infographic from One Block Off the Grid to compare CO2 emissions from various modes of transport.

BlablaCar is free for drivers and passengers alike to post trips / use the site.  The business model is based on taking a small commission (2eur / passenger / ride) on hundreds of thousands of trips per month.

The process is simple.  Let's say I plan on traveling from Paris to Bordeaux this Friday.  I type in my departure city and my arrival city and the date I plan on traveling.

Blablacar (branded as "Covoiturage.fr" in France) returns a list options based on the route and the desired date.  I click on the first result, which gives me a detailed profile of the driver and the trip.

Mika has an excellent rating (5 stars) with 33 reviews.  He likes to listen to music and chat ("blabla") and doesn't accept smokers. Perfect!

There's only one seat left in Mika's car so I sign up and reserve that last seat.  Easy, right?

BlablaCar is nominated for the EcoSummit Award 2012, an award for the best smart green startup (Brite and SolarFuel, two companies I wrote about last week are also nominated).  Out of 52 nominees, a whopping 9 are car-sharing programs, mostly German-based companies.

The car-sharing system is clearly easy to implement and can have an immediate positive environmental impact.  Now it's a question of form and reputation - who can design it best and reach out to the most people possible?  BlablaCar, with its ultra-simple interface and established community, definitely seems to have a one-up on the competitors.