It’s one thing to brag about your public transit system’s environmental bona fides. But the Polish capital city of Warsaw decided to rub it in everyone’s faces by having their new Inspiro subway cars designed by BMW too.

The Inspiro system from Siemens and BMW Group DesignworksUSA will go online in the Metro Warszawskie in 2012, boasting a number of environmentally sensitive designs.

The interiors are spaciously appointed with extra-wide entrances, for accommodating better passenger flow, large electronic displays for system maps, and lighting that’s placed at soothing intervals, rather than in blaring, monolithic banks. The electronics and mechanics cabinets have also been removed from the actual cabin walls — so that the interior space is as spacious as possible. And finally, you’ll also notice that the handholds are lit from above and shaped like tree branches — a symbol, the designers say, of the subway cars green ambitions.

Those green bona fides primarily come in the form of the carriage’s aluminum, “weight-optimized” chassis, which is significantly lighter than the average train car, reducing its energy consumption. And… wait for it… the carriages are expected to be 97.5% recyclable as well.