Let's face it UK driving standards vary from the sublime to the completely ridiculous,with that in mind and being unable to tell the idiots from the good drivers,I treat all drivers,and one or two motorcyclists too BTW,as potential killers.
I wear an Oxford hiviz vest and either a hiviz or white helmet,DLRs,main beam on motorways especially with a low sun behind me.
I suffer no illusions that they'll make me anymore visible to the ones that don't see me,but should I get wiped out,I or my N of K will have a strong case against the perpetrator.