Narrowly avoiding traffic

I was driving in the right hand lane of a curvy, poorly-lit, four-lane divided street the other night when I came around a corner and suddenly there's a guy coming right at me in my lane on roller blades, pumping hard! Pitch black darkness, no reflectors, no street lights, nothin. And there's a perfectly servicable, very wide sidewalk right off the street!

I see people make these mistakes on bicycles as well, and I think too many people just have no concept of how non-motorized traffic is supposed to work. You can use the street if you want, but you go WITH the traffic, not against it, unless you are walking.

The regular bicycle riders seem to get it; I guess it's mainly the inexperienced who don't know about this.