Or how about the one where a certain transit property stubbornly refused to use backgrounds on their color light signals - even on embankments above street level.

That is, until an investigator - Me, pointed out that this was the direct cause of a derailment. Seems that the red light had burned out, and had not been reported. At the same time, after dusk, a bluish-white mercury vapor streetlamp came on. It was visible to the motorman as he approached. But directly behind the signal!

He mistook that for a solid lunar aspect and blew right on by the signal into a misaligned switch. Oh - I forgot. They also insisted upon using solid (not flashing) lunar-white aspects on a medium high signal, to authorize "lined and locked" train movement, and also without stopping first; despite formal written protests from the signal design engineer that put it there.

Last I noticed, that damn signal still had no background on it, and still can be confused with mercury vapor street lights. Of course, they also insisted on putting the signals too close. So to make room for a signal background at this particular signal, it would have to be moved further away from the track, and apparently that costs more money than firing somebody.

Certainly, it costs more than locating it properly in the first place. But the big-shots always know more than any signal engineer - just ask 'em! But at least, newer installations have the backgrounds on them; unless the signal light is well below eye level of the motorman, so that only dirt is behind the view of the signal.

Still it amazes me, that college trained MBAs are always the slowest to learn; and still they always go scott free!