The pdf document attached to this page is an assessment of the reduction in carbon emissions that can be gained from changing from a traditional composite type of escalator step to a diecast one.
To keep the assessment relatively simple, no account has been taken of material that is not directly recyclable, but cannot be sent to landfill, (such as cast iron A-frames). It has been assumed that this material will be transported to locations relatively close to point-of-use by a Heavy Goods vehicle. Assessment of how much of this material can be recovered and recycled is beyond the scope of this exercise.
Please follow this link to see the difference that a cast step can make