Answer to the sign question

Guy's sister just reminded me that I never did give the answer to that sign question I asked way back in Wyoming. (Click here to see the original post.)

Here's the photo again:

Can you divine the meaning of these roadside markers?

These signs indicate to highway striping personnel exactly where no-passing striping changes should occur. The dots represent the dashed line, and the L shapes represent the solid line. In the photo above, the top marker means "the DO NOT PASS line in this lane ends here," and the bottom marker means "the DO NOT PASS line in the other lane ends here." Click here for a pretty little picture explaining it.