Difficulty of Identification of Official Tactile Walking Surface Indicators Using the Foot in Japan

Abstract

In Japan, following an accident wherein a visually impaired was hit by a train inside a railroad crossing, the installation of tactile walking surface indicators (TWSIs) at railroad crossings have become widespread. Attention and guiding patterns as well as escort patterns have been installed in front and inside railroad crossings, respectively. However, the extent to which the latter is more discriminable than the former has not been verified. This study determined the ease of identifying the Japanese official TWSIs and both patterns using the soles of the feet. Twenty blindfolded participants used TWSIs, scanned the raised surfaces with their soles, and responded to the type of TWSIs using three-alternative forced-choice. Compared with attention and guiding, escort patterns were misidentified with subjective sureness and long identification times. In about 90% of times that attention and guiding patterns were incorrectly identified, they were misidentified as escort patterns. The escort patterns were misidentified as attention patterns in about 70% of the times in which they were misidentified. Trials with misidentification had significantly longer identification times and lower sureness (but moderate sureness) than trials with correct identification. Approach angles to TWSIs had practically no effect on the identification. When escort patterns are installed inside the railroad crossings and attention and guiding patterns are installed outside, the visually impaired may misidentify them and accidentally enter or stay at the railroad crossing. Therefore, new installation methods to effectively identify all TWSIs, especially escort patterns, or develop new TWSIs with superior ease of identification should be verified.