THIS so much - Most of the public lights emit in +-all directions, making them not only uneffective but constant light polluters at the same time. And it would be so simple - reflect to the ground, say with 170° angle.

this would make the usual 'light cloud' over towns and villages practically disappear. I guess this is a remainder from times where the more light there was, the better (ie look at our mighty civilization and its advances, illuminating whole valleys and soon whole earth!). Now it makes it pretty hard to find unpolluted places in western Europe even in the Alps.

I can be in the Italian side of the alps, and I still get orange blobs from Switzerland or France, even across continuous wide range of frikkin' 4000m peaks!