(1)
Where a tactile attention indicator is required, it shall conform to Sentence (2) and Clauses 5.1.1. and 5.1.2. of ISO 23599, “Assistive Products for Blind and Vision-Impaired Persons – Tactile Walking Surface Indicators.”
(2)
The depth of the tactile attention indicator shall be not less than 300 mm and not more than 610 mm.