Chapter 11 is titled 'Accessibility' and covers requirements for the layout of a building and site. The purpose of this chapter is to require a design with features that are reasonably functional for people with physical disabilities, such as, but not necessarily limited to, mobility, vision, and/or hearing.
The model shows a ramp which provides an easier path between different elevations, versus trying to use the stairs, for someone who uses a wheelchair, walker, or cane.