Barriers and obstacles in public spaces restrict the mobility of wheelchair users. This physical disability results from the incongruity or gap between the individual abilities of the wheelchair user and the environmental demands. Location based mobile services that offer information on demands of certain paths can support wheelchair users to navigate in a foreign city ac- cording to their individual abilities. The proposed model of barriers and obstacles for route planning allows a wheelchair user to estimate individual physical demands of a path in computer -based route planning.
The validation of this hypothesis led to the following results:
- An Essential Model describing barriers and obstacles for wheelchair users.
- Requirements for navigation services for wheelchair users.
- A description of three navigation services for wheelchair user.
- An Abstract Model as a basis for the implementation of these services.
- A protopical implementation of the services.
To develop the model, barriers and obstacles in public space were identified through the analysis of research, standards and recommendations for engineers and architects and maps. Experts and wheelchair users were interviewed to find out which information is necessary to allow the estimation of an obstacle's physical demands. The resulting Essential Model describes obstacle object classes by means of their constructional attributes together with special constraints that make a specific object an obstacle.
To integrate this model into a computer-based service, scenarios, describing wheelchair user navigation, were analyzed and led to the following list of requirements for specialized navigation services:
- It is necessary for wheelchair users to know which paths they can use and how these paths are connected.
- Existing barriers must be taken into account for route calculation.
- The evaluation of barriers must depend on individual physical abilities.