Design for Accessibility: The Development of Public Transport Vehicles with Regard to Mobility Impaired Passengers

Doctoral thesis, 1993

The objective of this thesis is to show how a knowledge basis and requirements for vehicles, for the accommodation of mobility impaired people, can be worked out and specified through experimental studies with selected groups of subjects as well as how requirement specifications can be formulated for use in the development process of vehicles. The overall hypothesis underlying this thesis is that integrating the requirements of mobility impaired people in the normal development process of vehicles produces a superior vehicle compared to redesigning or modifying a complete vehicle. A working method for the development is proposed, based on the development process used by vehicle manufacturers and on a user oriented product development process, focusing on the analysis of the user in the use situation. The work contains experimental studies of defined subsystems of vehicles, carried out with selected groups of subjects, for the purpose of specifying the functional requirements on the shape, dimensions and performance of the systems. The experimental studies have dealt with entrances and seats in buses, entrances of taxi cars, wheelchair and occupant restraint systems and the traversing of step obstacles with manual wheelchairs. A description and analysis of the development process of vehicles and a user oriented product development process are presented as well as a case study showing an example of how to define a requirement specification for buses based on the results of the experimental studies carried out. Principles for the selection of test subjects, methods for the recording and analysis of data as well as for dealing with conflicting requirements are discussed.