The real route sets the safety direction
A barrier, bollard, gate or active system only makes sense after the movement in the area is clear. Who walks there, which vehicles pass through, where they turn or reverse, what can be struck and how much working space remains.
The right direction depends on the real area: pedestrian separation, impact protection, loading-bay safety, active warning or infrastructure protection. For an independent view of the wider system, see the HSE workplace transport safety guidance.