Its another of them little things that amuses you in the sense that staff can,t rely on a crossing as a warning for trains approaching them due to all the above items as described by tempest 1 , but a job we had to inspect a pump / water level if it failed that was on the edge of the crossing down a hole beneth a sink lid , we used to get the signalman to drop the barriers so that we could lift the lid and look down the hole to protect us from the traffic.
Another little sideline to it is if its not safe for staff to rely on barriers etc! is it safe for the public and cars to cross the crossing then?
Could one of them rouge trains running wrong direction movement when the crossing fails and the red lights fail be coming across in the road traffics way? ( A little funny haha)