I remember reading somewhere in the discussions which I linked to that the bench ended up being at that height simply because the nearest structural pipe (to which it is welded) is there, and all models of the bus stop have benches at different heights because of where the skeleton happens to be (and most are much too high). I don't know if that was part of Lebedev's brief.

Anyway, Lebedev apparently didn't give much thought to how these stops would actually be built (or used, for that matter), leading someone to say that the sketch was by Studio Art. Lebedev, but the actual industrial design was by Vasya the welder - who had no choice but to pick up the burden where the Studio dropped it.