What's all that white stuff?

What's with the half painted poles, you might ask? So they stand out to those driving on the road, incase one should veer to the sides - whoa! A big white POLE! The bottom 5-6 feet of most concrete lamp posts, and other side-of-the-road objects are painted white here. This includes these huge rocks. Some rocks don't even need to be close by the road to become hazzardous to our motorists apparently, I have seen them painted white as far as 100 yards off the road, although this may be more for asthetically pleasing reasons than for safety. Not that white stays clean very long in a city with all this gook floating by in the wash-out rains plague us May through August, as well as of late. Most of the time, you see the nice white paint that fades into grey/brown dirty on the bottom 3 feet. These rocks appeare to be freshly painted, and therefore stand out. I would surely not hit them, if I were a crazy careless driver.