The Swedish parliament has decided that the public transport should be available to disabled people by 2010. For the visually impaired, one major barrier to an accessible public transport system, is the fact that a majority of the information regarding public transport is visual. The visually impaired is therefore by default less mobile and often avoiding travel with public transport by themselves. TFK started in 2001 a project with the long-term aim to develop a guidance system, which uses spatial information and real-time public transport information to enlarge the possibilities for the visually impaired to travel alone.
The company Voxit together with Cartesia and TFK has developed a prototype of a guidance system. The prototype consists of standard components, which include a small wearable computer, GPS, DGPS, digital compass, GIS and program for speech recognition and speech synthesis. The accuracy of the positioning in the prototype is ±0.5 meters. The GIS-software handles the user's real-time movements and provides information to the system concerning which way the user should go. The prototype also gives information regarding the surroundings, hazards and obstacles. The system also includes simulated real time public transport information. As a result, the user can choose a departure and then be guided to the nearest bus stop.
The aim of this part of the above guidance system project, initiated by TFK, has been to develop, test and evaluate a guidance system.
A user group consisting of 13 visually impaired persons has tested the prototype in the area of Framtidsdalen and Borlänge city.
The evaluation of the demonstrations shows that the users clearly see the benefits of such a system. Since the technology used in the prototype is new, some technical problems occurred. Most of the problems were related to the positioning system, i.e. lost in GPS-signals.
The assessment showed that the response to the information given by the system were largely dependent on the sight ability. The blind persons were able to follow the instructions better than the partially sighted persons who experienced a conflict between their own perceptions and the instructions given by the system. This especially applied in open surroundings without contrasts or guidance paths. The assessment also showed that a majority of the test persons felt safer with the system than when they usually do while moving in unknown environments.
The information given by the system must be limited in order to avoiding distracting the user and overloading the system. For example, the real time information given by the system about the time left to the departure was considered too frequent by the users and also prevented more important information to reach the user.
It is important that existing spatial data also includes cycle paths and footpaths with attributes representing guidance paths, obstacles, hazards and so on.
A guidance system is wanted by the visually impaired but there are still many obstacles to be cleared before a system with detailed information can see widespread use. The technology should not replace existing means of assistance. Instead a guidance system must be regarded as supplementary to other navigational aids such as white canes and guide dogs. However the visually impaired taking part in the project see a wide range of use with such an aid in their daily life. It is also believed that the system will give them a greater freedom and less need for personal guidance.
The project with the guidance system will continue with the aim of developing a smaller sized system that can be adapted to existing technical products like a PDA or a mobile phone.