I used to deliver goods to Albermarle Barracks. I was never vetted nor my van searched. The general procedure was that you given a card to stick in your window stating 'visitor' or 'contractor' whilst making your deliveries. On occasion, I was asked to sign a log, but I always got the impression that was only done when they were expecting someone important therefore the correct procedure had to followed.

As for the bus, well, after the last 'public' bus stop I'd imagine it'll be mostly squaddies and their families left on the bus. Although it would be presumptuous to assume everybody knows everybody else on camp, I would guess that at least one other person who could vouch for you. Any strangers on board would probably be scrutinised by those on the bus before it reached the camp.

Just a guess.