As an avid amateur astronomer, the mitigation of light pollution is one of my passions, notably dovetailing with my professional passion for efficient design. The most efficient outdoor lighting concentrates its light on the ground rather than illuminating the sky. Actually, the most efficient outdoor light is one that is turned off, except when needed :=)
Here's something I bet you weren't aware of. I know I wasn't....Most European cities turn off or dramatically reduce street lighting overnight, especially on secondary roads and outside urban areas. But not Belgium, and it's getting called out for this. The below-linked article in the NY Times involves an astronaut, electrical supply and distribution monopolies and political cronyism to a degree I never imagined.
I read the same article. Nothing of technical interest, but the policy side of me loved it.
Every economist knows -- incentives matter. "It is difficult to get a man to understand something, when his salary depends upon his not understanding it!" -- Upton Sinclair