Since you bring up streetlights, I was driving back in from a BC trip a few weeks ago, and with the contrast of the lower mainland, I was a bit baffled how unlit the Yellowhead is as it comes into town. Usually i'm not out that way when it's so dark so I hadn't noticed before.
From approximately Spruce Grove, I was finding that the light of the urbanized areas along the highway was forcing my eyes to adjust to slightly higher light levels, and thus the Yellowhead itself being unlit in this area made the road seem especially dark.
By Contrast, the QE2 from the south is pretty well lit after Leduc, and it's very much appreciated. It seems a bit odd they haven't lit this portion of the Yellowhead, but I'm not really familiar with the decision making for road lighting on provincial highways.