i was up i apple valley for some parts a few months ago and rolled back to LA via 138 that evening. at night, even though it is a major highway there are parts that are totally unlit and you're not seeing more than 30 foot or so past the shoulder; and there are whole miles long stretches of nothing.
anybody could be doing anything up there under the cover of darkness and nobody would have the slightest idea.
not to mention, you're not exactly out for a sunday drive on that piece. it's one of the most dangerous stretches of road in california, people drive fast and there's a lot of undivided areas with no shoulder so you ain't rubber neckin' if you see something out in the brush.