If you were very familiar with an old mine, and were aware of rocks moving, or timbers cracking, or walls flaking, and that such things were really only apparent to you and your colleagues as you had noticed these changes, how would you let others know, because they might happily visit these features in blissful ignorance of the potential new dangers? Lets say these worrying changes happened on a regular trade route. How would you feel if someone was badly hurt or killed by, say, stacked deads giving way? You, of course had seen some weeks earlier that a timber had shifted, or part of the deads had moved. Others would not know of this unless they too were frequent and observant visitors. The answer surely is to use your best judgement as to whether some visible warning might be appropriate. A well-placed tape might be the easiest and most effective warning measure. Why else do the Police use blue and white tape to keep people off places being investigated? Because it works.
