As part of this year’s Art On Track festival in Chicago, local design grad Joe Baldwin greened an elevated subway car that cruised the windy city’s tracks for several hours. Critics might argue against it here, saying that converting a Skytrain car into a lush, botanical paradise would be taking our Mayor’s “greenest city” initiative a bit too literally, but an art installation is just that, and few things are more comfortable than shrubbery. More images here.