Folding Bus Doors

Bus doors such as this one can be built in RoR.

Here is an example truck, using a sarrus linkage for the effect

BusDoorDemonstrationForWiki.truck

here is an example truck designed to show the mechanism: Parts have been colour coded.

Light brown: frame
green: Door faces
yellow: frame to stop door folding in on itself
Red: Frame to keep door in line. Forms a sarrus linkage with the green and yellow door.

ColourCodedBusDoorDemonstrationForWiki.truck