Experiments were conducted to address issues regarding the laydown of tactile ground surface indicators (TGSIs) (i.e. textured paving blocks) for the visually-impaired on station platforms. This is outlined in the Guidelines for Implementing Smooth Passenger Flow in Public Transportation/Passenger Facilities (hereafter referred to as the guidelines), which was supervised by the Ministry of Land, Infrastructure and Transport and provides guidelines for facility implementation and maintenance based on the Traffic Barrier-Free Law.
      Experiments were conducted to investigate the lower limits of TGSIs spacing at the platform edge of a narrow island platform (A in Fig. 1) and the upper limits for positioning warning blocks at the platform edge (B in Fig. 1).These experiments were carried out with the help of 35 totally blind people who use railways alone with a long cane.
      The tests showed that it is desirable to:

(1)	secure in principle 60 cm or more as the lower limit (A in Fig. 1) of TGSIs spacing, or at least 40cm or more in case 60cm is not applicable.
(2)	secure the upper limit (B in Fig. 1) of TGSIs position in a range between 80 and 100 cm.

      The experiment for the lower spacing limit in (1) was conducted by crossing TGSIs of Tracks 1 and 2 on the simulated platform perpendicularly, and stopping immediately after detecting the Track 2 block. As shown in Fig. 2, the stop rate exceeded 90% when the spacing of the protection area lines was 40 cm, and reached 99% at 60 cm.
      During the experiment for the upper limit of TGSIs positioning in (2), participants were asked whether or not they felt a surprise or danger due to the distance change when they experienced distance of 80 cm from the platform edge, (the current lower limit), after sensing feeling at various distances over 80 cm from the edge. As shown in Fig. 3, over half of those who first sensed feeling at the distance of 110 cm felt surprise at the 80 cm mark.
      Relevant data was also collected and sorted for use in guideline compilation, including notes on the laydown of the platform edge protection area warning block line (C in Fig. 1) that distinguishes the inside (i.e. the safe side) from the outside (track side) of the platform.
      These results were reflected in an additional version of the guidelines published in December 2002.
      This study was conducted with a subsidy from the Ministry of Land, Infrastructure and Transport.