I was watching a TV program about the USA when the speaker said proseguiamo nella scoperta delle strade blu ("let's continue in the discovery of blue roads"). I didn't follow the program since the beginning, but the part I watched was talking of Route 66. Since strade blu is not an expression used in Italian, I thought the speaker was translating an American expression.
Is blue street an understood way to refer to a particular type of street? If I am describing a travel I have done, and I say "I took the blue road" (after making clear where I was exactly) when describing the path I took, would I be understood from American native speakers?
For example, would the following sentence be understood?
At the cross between William Floyd Parkway and Long Island Expressway, I took the blue road in direction of Flanders Bay.