geometry of a space. Furthermore, information about doors or
elevators can be mapped by adding a node to the corresponding
building part way. The composition of a detailed floor plan
for a building level with rooms, corridors, doors is depicted in
Figure 2a. Vertical passages –such as stairways or elevators–
are represented as ways connecting nodes at different levels.
In order to store semantic annotations in each OSM building
element, retaining backward compatibility, new tags were
introduced in [11] complying with the basic key-value pair
structure of OSM element tags:
.
The semantic prefix is used to distinguish semantic
annotations from other tags. The index n identifies different
annotations –possibly referring to different ontologies– associated
to the same map element.
Figure 2b shows details of accessibility issues annotation.
The following tags have been used:
– denoting
whether the element is accessible to people in wheelchairs;
–
denoting whether people with disabilities can pass through
a barrier, i.e., a door, an elevator or a stairway. The
permissive value indicates the need for assistance from a
companion: this is the case e.g., of firewall doors.