Roll-down door arrangements

A cargo vehicle, comprising:

• a) a cargo compartment, the cargo compartment including:
• i) a floor;
• ii) a plurality of adjoining walls extending upwardly from the floor;
• and
• iii) a ceiling attached to an upper end of the plurality of adjoining walls, wherein the walls, floor and ceiling cooperate to form the cargo compartment and a first vertical opening having a width defined by first and second sides for accessing the interior of the cargo compartment;
• b) a first segmented retractable door proximate the first vertical opening of the cargo compartment;
• the first door being displaceable from a first vertically-oriented closed position in which the door covers the first vertical opening, to a second open position in which the door is substantially disposed below the first vertical opening;
• c) a first track adapted and configured to receive a first side of the first segmented door, the first track having a first vertically oriented segment disposed along the first side of the first vertical opening;
• and
• d) a second track adapted and configured to receive a second side of the first segmented door, the second track having a first vertically oriented segment disposed along the second side of the first vertical opening, wherein the first segmented door is downwardly displaceable along the first and second tracks from the first position to the second position.