system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What do those bristles on the side of escalators do?
gpt
There was a fire in Kings Cross underground station in London where a lit match used to light a cigarette was thrown down where the bristles are now and fell between the outside rail and the escalator steps landing on the greased runner lighting the grease on fire. There was several things done to prevent such a tragedy from happening again. One of which had already been done which was to ban smoking in enclosed public spaces although this was enforced better. The bristles on the side of the escalator was another effort as it will deflect cigarettes and other debris away from the gap and onto the steps so that they can easily be cleaned up rather then falling into the machinery of the escalator. It also have a few other minor advantages such as preventing people from standing all the way on the edge.