is
Whether traffic with business elsewhere has to pass through this zone.
A fact about the layout and not about who happens to be standing here, so it is answerable at any instant -- including the instant a transporter stops, when nobody has yet had time to queue up behind it.
A spur is the exception, and it is the exception the guide path already recognises: a dead end is entered and left the same way, so nothing passes through it, which is what makes a spur the standard device for keeping a stopped transporter out of everyone's way. Its zones are refuges, and so is the junction it ends at, because that junction leads nowhere else.