escalator step width

The step width of an escalator is the distance from left to right across its steps, measured in a line perpendicular to the direction of its motion. This width does not include any part of the rails or housing except those parts overlapped by the steps. This measurement may be applied to a structure or to an area with multiple escalators only if all escalators within the defined boundaries have an equal step width.

The step width describes an individual installation. For a structure or area containing several escalators, the common value applies only when every installation has the same step width.

A maximum or average of differing measurements does not express that common value. Replacing an installation with one having a different step width removes the condition of equality stated above.