Architecturally, glass stairways have an aesthetic of their own, but intuitively they seem more dangerous than regular stairways. So are they, and if so, by how much?
An observational study of two public stairways, one glass and one concrete, showed that the glass stairway had significantly more incidents. This was in spite of more caution being used on the glass stairway. Indeed, they were eight times more likely to have an incident.
Encouraging people to take the stairs is one of the proposed strategies of healthy built environment movement. But if the design excludes users because of the design, or is less safe, this is discriminatory. And yes, there might be an elevator, but this is not equitable access. Regardless, everyone should have the opportunity to use the stairs if they wish.
The title of the study is, “The effects of glass stairways on stair users: An observational study of stairway safety”. It is open access on Academia, or you can download the 2MB PDF file. There is an earlier stairway study on ResearchGate, “The effects of interactive stairways on user behavior and safety” by the same authors.
Abstract: The purpose of this study was to assess the safety of a winding glass stairway by observing the behavior of stair users and to identify issues that should be studied in a laboratory setting. A checklist for coding stair use behaviors was developed. Video observations were conducted in a retail store with a glass stairway (GS) and a shopping mall with a conventional stairway (CS). Key behaviors related to safety (tread gaze, diverted gaze,handrail use) and stair incidents on the two stairways (GS and CS) were identified from the recordings and compared. On the glass stairway, more users glanced down at the treads (GS: 87% vs. CS: 59%); fewer users diverted their gaze away from the stairs (GS: 54% vs. CS: 67%); and handrail use was higher (GS: 32% vs. CS:24%). Incident rates were much higher on the glass stairway (6.2%) compared to the conventional stairway(0.7%). Walking on winding treads made of glass may be more dangerous than walking on conventional materials due to reduced visibility of the tread edge or reduced friction between shoes and treads. Recent laboratory research suggests that stairway users may behave more cautiously using stairways with glass treads but the results from this study demonstrate that the benefit of increased caution can be negated in real world conditions.