Such techniques are also implemented in Chinese national rail and virtually every subway system (which is now arguably the most complex on the world albeit suff

Such techniques are also implemented in Chinese national rail and virtually every subway system (which is now arguably the most complex on the world albeit suffering from under-educated employees). It certainly have some merits. I also personally feel it's useful for some repeative but critically important tasks. Now I have the habit of pointing at the all the lasers/amplifiers while checking them are off before leaving my lab.