Airplanes, trains, and cargo ships may travel through different mediums, but they roughly do the same thing: encase precious cargo in a similar container, and then unload it at the destination. "Clip Air" is a concept from Switzerland's Ecole Polytechnique Fédérale De Lausanne that wants planes, trains, and ships to carry people much the same way they carry shipping crates: in detachable, modular tubes, which can be put on rails, loaded on boats, or slung under wing.

EPFL explains the benefits:

The decoupling of the load (capsules) and carrying units (wings) allows for simplified fleet management and maintenance operations for airlines and is expected to improve the ground operations for airports. Clip-Air also provides effective possibility of combining commercial freight and passengers on the same flight without any compromise in comfort. Besides, Clip-Air is designed to operate in a multi-modal context and is expected to improve the multi-modality concept by allowing a better integration between air transport and other transport modes.