Studies of the tactile ground surface indicators for visually impaired person at railway platform

Osamu Sueda, The University of Tokushima,
Masaki Tauchi, Okayama Prefectural University,
Toshikazu Kato, Nippon Lighthouse,
Yosihiko Sasagawa, Japan Federation of the Blind,
Tetuji Tanaka, Japan Braille Library,
Shinji Ariyama & Koji Yamamoto, East Japan Railway Company,
Haruki Shimizu, Tobu Railway Company,
Tatsuo Arakawa, Tokyo Metropolitan Government Transport bureau,
Akira Shinomiy, Railway Technical Research Institute.

"Guide/Warning block improvement investigative commission" of The Ministry of Transportation carried out following three researches on the structure for installation of tactile ground surface indicators, TGSI's, on railway platform.

  1. The maximum distance between the platform edge and TGSI's was studied. In Japan, TGSI's shall be placed 80cm or over back from platform edge. We performed an experiment with 34 blind persons, asking them whether or not they felt "astonishment (or danger)" because the distance was shorter than they had expected. As the result, we determined that the distance shall be maximum 100cm as a rule.
  2. The special structure of TGSI's at the edge of platform was designed to notify the direction toward/against for the edge. As the result of study, we determined that one linear protrusion line neighboring at 9cm from the dots on the safe side of the platform shall be installed for direction.
  3. The lower limit of the interval between two TGSI arrays was studied to prevent the fall-down from another side of edge at narrow platform with 35 blind persons. As the result, we determined that the ideal interval is 60cm, or at least 40cm or over in case 60cm is not applicable.