Black Dog

Long before the game of finding mathematically significant road signs, this sign used to always catch my eye. Black Dog Road. It sounds like a place where some mystery happened years ago. If you were sitting around a campfire with your grandpa you could easily envision him whipping out a story about the Ghost on Black Dog Road. This entire scene is filled with stories waiting to happen. Burnsville itself brings overtones of fire. Add to that Cliff Road and you've got the ingredients for a great ghost story. Maybe even a ghostly poem of terror.



The math here is a little elusive. We can remove the A and B from 4A and 4B and just use them as fours. Your eye can get distracted with the 2nd 4B and 15 MPH signs, however, they are independent signs and do not invalidate our main sign. After clearing these unrelated signs and leaving the stories of mysterious black dogs behind, the math becomes clear.

$$( 4 \times 4 ) -1 = 15 $$

This sign was found on 35W Southbound heading towards Burnsville, in Minnesota.