The Millbrae transit station has this circle of tilework in the middle of the lobby.  It's polished to a glossy finish, as you can see, and surrounded by ugly pylons because... i don't know.  I'd guess that it's so smooth that people slip on it, so instead of finding an attractive way to reduce, eliminate, or secure traffic, the attractive slabs are instead marred by yellow caution tape.

There's more than a few things at work that echo this.