The tracks at AirBnB are a cool feature, but on close inspection of the photo they look like the decorative concrete "tracks" used in several places recently. Note that there is no frog ("rails" simply run into each other) and no real points. Similar "tracks" can be found in the light rail station-plaza area of Historic Folsom and along the reconstructed (for urban renewal) portion of R Street (between 10th and 15th) in Sacramento. I guess it's possible that they assembled the feature using carefully cut rail before burying it in concrete, and the "tracks" in R Street look a lot like real rail (they did have some available after tearing up the old street), but I know for a fact that the Folsom "tracks" are fake (until you get to the turntable; there is an actual track after that for the displayed museum cars) and they look very much like these; in the Google street view you can even see some of the paint starting to wear off the Folsom "tracks" in the street. If you're going to have a track-like design feature, the concrete version is probably safer to walk around than real rail, and certainly easier to maintain.