[rando_dfad]

> Yes there is, it's crime. Street lights deter crime.

> Also simply driving safety. Driving with just headlights causes more accidents than on a well-lit street, since visibility is so much worse.

Accepting your points for convenience, wouldn't we get the same benefits with lights that only pointed downward? And if you further restrict to warmer colors (which interfere less with low-light sensitivity, also less diffraction reducing light pollution), with a sensible but low max intensity (again keeping the human eye more dark-sensitive, allowing better visibility into the non-illuminated spaces)?

Reducing nighttime lighting by 50% would make a huge difference in sky visibility.

[alexb_]

There's a lot of streetlamps that switched to early versions of LED bulbs that start glowing purple as they age. I've actually really come to like the purple color illuminating streets, it's much easier on the eyes than the bright white.