Expert Study: Design and Use of Textures for Tactile Indoor Maps with Varying Elevation Levels

Tactile maps could increase the mobility of people with blindness and visual impairments. Most research on the design and development of tactile maps focuses on outdoor environments, whereby indoor environments greatly differ in terms of represented objects, structure, information, and purpose of use. Studies on the design and use of tactile indoor maps are missing, so it is still unclear how textures can be used effectively in tactile maps and which are suitable for which areas and contexts. As a first step, we therefore conducted an expert user study with four blind participants to determine the challenges and benefits of textures in tactile indoor maps. Afterward, we initiated a follow-up study with two experts from the initial study to evaluate the influence of different elevation levels and production methods (swell paper and embossed maps) on the recognition of different textures, symbols, Braille labels, and structure of the building. We observed an influence of the elevation level of the texture on the recognition of map elements. Furthermore, the perceived structure of the texture influences the recognizability of the map elements. As a result, we identified suitable types of textures for rooms and floors in tactile indoor maps.