I did a search for this topic, but didn’t see anything relevant. Google wasn’t much help either, turning up mostly irrelevant links with only a couple that mentioned the topic but did not actually explain anything.
The question is this: while driving in the mountainous desert north of Los Angeles, I once came upon a traffic sign I’d never seen before. It indicated that drivers were to turn on their headlights in the daytime, while traveling through a specified distance (something along the lines of “Daytime Headlights, Next 11 Miles,” but I forget the exact wording).
I’ve heard lots of talk about the merits of daytime running lights for cars, but it seems those advantages would apply anywhere, so why not just make a law about it and bag the signs? It seems to me there’s got to be something peculiar about that particular stretch of road. But, at least to me, there didn’t seem to be anything “special” about either the road, or the terrain surrounding it, other than that it was pretty isolated. I was thinking, since it was the desert, that maybe from time to time there was enough dust in the air to at least partially obscure an unilluminated vehicle, but surely drivers would notice that condition and again, the law could instruct accordingly. So my question is, simply, why?
Thanks in advance for your replies.