because, if it is accepted ‘in this one case’, then others will want the same in the same circumstances, and one case becomes many.
Where else in the country does a road cross 3 level crossing on 3 different rail lines in little more than a quarter of a mile? I'm struggling to think of another example. Ely North/Prickwillow Road is a unique circumstance.
Even if that were not the case, common sense would say if alternative mitigations are acceptable at Ely, they may well be acceptable elsewhere.
Also, one day, there will be an incident at the crossing. And someone who signed off the change will have to stand in front of the judge to answer the question from the prosecution “the risk assessment showed that the risk assessment of an incident increased by x, and you chose not to implement the proposed mitigations That would reduce that. As the controlling mind, that makes it your fault. How do you plead To the charge of manslaughter by gross negligence?”
if you think I’m scaremongering, I’m not. I know people who have been through this (or the precursors to it).
In that case the crossing should be closed now - you've said it yourself - one day there will be an accident.
Surely the person who signed off would be able to say "Well, we mitigated it by putting in full barriers with obstacle detection. There was no other cost effective mitigant. The deceased deliberately chose to ignore flashing lights, beacon, and the gates and trespassed/drove onto the railway anyway. Therefore fault lies with the deceased."
Why does the railway fret so much over these theoretical issues when in other sectors blatantly unsafe stuff like "smart" motorways gets signed off, people get killed far more regularly than at level crossings and everything's fine?
Is it not just possible that the railway goes a bit over the top on these things?