This might just look like an alternative visualization of those composite images of the Earth from space at night, but what's nifty about this is that it purports to also show just how far from populated areas one would need to travel in order to maximize darkness.
The entire map is the light pollution. The key there at the top of the screen. Find where you are, and look at what color the area is around you on the map. From personal experience, if you're in a downtown metropolitan area that the map shows as white, then you'll be lucky to make out Betelgeuse or Rigel in Orion, Sirius would be visible, as well as Venus, Saturn and Jupiter. Anything fainter than that will be difficult. Using binoculars will improve things quite a bit though. As you start to get into the orange colors, all of the stars in Orion would be visible. I have been able to make out the Milky Way in yellow areas. In the blue areas, I can see the Milky Way quite clearly. In the black areas, it takes me a bit of time to adjust to find Orion/Big Dipper/etc because there are now so many stars visible that the very obvious constellations are harder to see immediately.
I live in the middle of the giant cancer of light pollution that is the Netherlands/Belgium/Germany triangle. Most of Belgium is on the white-ochre spectrum. There are no dark spots to speak of within any reasonable distance. It's depressing.
What common light pollution map is this referring to? The only images that I've seen of this nature are photographs of the Earth from space at night, which do a good job of showing where the light is but a less good job at showing where the darkness is. Though I doubt this map is taking geography into account, it appears to be a clearer indicator of the distance from well-lit areas such that e.g. one could reason that in order to see a dark sky in the US one would need to be no farther east than Nebraska. I can't argue as to its true accuracy, I just submitted it to see if anyone else might find it useful. :)
Just google "light pollution map", NOAA has been producing them since at least the 90's. We used it for our astronomy club when we purchased property for our observatory in 2000. At the time it was the only blue area on the map within 1 hour drive. Unfortuatley there's no blue areas within a 2 hour drive now :(.
