Risk assessment must have to take into account context. What is acceptable on the ground is not when someone is working on a roof, but people have to work on roofs.
The TT, and other dangerous sports, are undertaken with an understanding of that. The risk assessment must then look at the unacceptable i.e. avoidable risks.
If context is not used then nothing is an acceptable risk. e.g this computer I am working on could, potentially, elecrocute me. (ask TTwebsite member "fly" about that!!)
However, it is insulated etc. If I were to go out to the nearby electricity substation, I could relatively easily arrange my electrocution, but signs both on the casing of my computer, and on the walls of the station warn me against those actions.I am expected to obey these.. and so in the context of racing etc.
So far we have not banned computers or electricity substations, but if context were not taken into account, we might find them unacceptably dangerous.
Of course, we have to ensure that the "insulation" and "signs" are accurate and fit for purpose.
(Whew... think I have been working too long this morning... that got a bit academic, eh?)