Speed kills when used at the wrong time in the wrong place ,or in the wrong conditions.
Obviously driver skill comes into this equation.
I am a retired police driver,so have been trained in advanced driving,so I think I can comment.
It is very rarely a good idea to drive at these sort of speeds on a busy motorway,as other traffic is unaware of the speed of approaching cars from behind.
Only if you have been trained to do so safely,then you are relatively safe to do so. IMO