TWSIs should never be used at escalators or moving walkways because these devices are reversible. The presence of TWSIs may cause congestion at the exit of an escalator or moving walkway resulting in a safety hazard.
The comb plate (i.e., surface closest to the escalator or the moving walkway, both as you step on and step off) should be marked with a colour/brightness-contrasted strip that runs the width of the step or walkway and is a maximum of 50 mm deep.
A low-level warning sound should mark both ends of a moving walkway. A person with vision loss should be able to hear the warning 920 mm before the transition between the moving walkway and the floor. Any audible warning indicators should be adjustable for environmental noise such as crowds.