So I noticed that my photo of some London Underground Victoria Line seat fabric has had (as of today) 294 views, and has been favorited 3 times. To me, that's a surprising amount of attention for something so... everyday. Maybe I've tagged it cleverly. No, just checked, and not really. I suppose trainabilia is just popular, as well as a word I think I made up. Also, colours and pattern, ooh.
You can actually buy this fabric at the London Transport Museum Shop. It's called "moquette" which is a type of woven pile fabric in which cut or uncut threads form a short dense cut or loop pile. As well as giving it a distinctive velvet-like feel, the pile construction is particularly hard wearing and ideally suited to applications such as on public transport.