Existing pedestrian navigation systems are mainly visual-based, sometimes with an addition of audio guidance. However, previous research has reported that visual-based navigation systems require a high level of cognitive efforts, contributing to errors and delays. Furthermore, in many situations a person’s visual and auditory channels may be compromised due to environmental factors or may be occupied by other important tasks. Some research has suggested that the tactile sense can effectively be used for interfaces to support navigation tasks. However, many fundamental design and usability issues with pedestrian tactile navigation displays are yet to be investigated. This dissertation investigates human-computer interaction aspects associated with the design of tactile pedestrian navigation systems. More specifically, it addresses the following questions: What may be appropriate forms of wearable devices? What types of spatial information should such systems provide to pedestrians? How do people use spatial information for different navigation purposes? How can we effectively represent such information via tactile stimuli? And how do tactile navigation systems perform? A series of empirical studies was carried out to (1) investigate the effects of tactile signal properties and manipulation on the human perception of spatial data, (2) find out the effective form of wearable displays for navigation tasks, and (3) explore a number of potential tactile representation techniques for spatial data, specifically representing directions and landmarks. Questionnaires and interviews were used to gather information on the use of landmarks amongst people navigating urban environments for different purposes. Analysis of the results of these studies provided implications for the design of tactile pedestrian navigation systems, which we incorporated in a prototype. Finally, field trials were carried out to evaluate the design and address usability issues and performance-related benefits and challenges. The thesis develops an understanding of how to represent spatial information via the tactile channel and provides suggestions for the design and implementation of tactile pedestrian navigation systems. In addition, the thesis classifies the use of various types of landmarks for different navigation purposes. These contributions are developed throughout the thesis building upon an integrated series of empirical studies.

Persons with visual impairments often rely on navigational electronic aids, which typically employ speech commands for guidance through novel routes. However, navigational speech commands may interfere with the perception of acoustically rich environmental information, resulting in potentially detrimental effects. We investigated the sense of touch as a means to convey navigational commands instead. The somatotopic representation of the body surface within the central nervous system makes spatial information intuitive to our skin, suggesting that the tactile channel should be equivalent to, if not better than, the auditory channel at processing directional commands. Additionally, based on Wickens’ Multiple resource theory, the tactile channel should mitigate the sensory load in the auditory channel in travelers with visual impairments. We tested the ability of blind users to process directional commands conveyed via a tactile navigational belt. 14 blind participants were tested with the tactile belt under conditions of either low or high acoustic sensory load, simulating different outdoor environments. For comparison, the same participants were tested also with a conventional auditory device. Consistent with previous studies, we found navigation with the tactile belt to be less efficient than navigation with the auditory aid in the absence of environmental sounds. However, we found also – for the first time, to our knowledge – that tactile performance was less compromised under conditions of high acoustic sensory load. These results will help to inform the further investigation and development of tactile displays to benefit blind travelers. / Thesis / Master of Science (MSc)