Detection of warning surfaces in pedestrian environments: The importance for blind people of kerbs, depth, and structure of tactile surfaces

Abstract

Purpose. The overall purpose was to study whether and how persons with blindness detect warning surfaces with a long white cane in a real pedestrian environment after following a natural guidance surface to the warning surfaces. Of particular interest was the importance of kerb, depth, and structure of the warning surfaces.

Method. A concurrently mixed methods approach, with a combination of observation using a structured form together with ‘think aloud’ and a structured interview, was used. It was done with well-defined samples and study sites in an inter-disciplinary research context.

Results. The results show that the most important design characteristic for detection of the warning surfaces with a white cane is the structure of the surface, while the depth of the surface and availability of a kerb do not have any impact on the detection. A precondition was that there is a distinct natural guidance surface leading up to the warning surface.

Conclusions. The probability among pedestrians with blindness to detect a tactile surface is not higher if the design solution has a kerb. This study also confirms the complexity of being a blind pedestrian in the traffic environment. The results can be used for evidence-based physical planning. The study also has implications for development of more efficient vision rehabilitation.

Keywords:

• Blindness
• kerb
• crossroad design
• pedestrian environment

Acknowledgements

The authors thank the participants who took part in the study, without whom this research would not been possible. They also specially thank LicSc Vibeke Horstmann for valuable input and help with statistical contribution and analysis, and to Occupational therapist Kristina Holmberg at the Low Vision Centre in Falun for contacting subjects and conducting the assessments of functional limitations and the interviews with all the participants. They also thank both the Swedish Road Administration and the Swedish Rail Administration for financing the project, and to the municipality of Borlänge for its support. The study was conducted within the Centre for Ageing and Supportive Environments (CASE) at Lund University, financed by the Swedish Council for Working Life and Social Research.