Is "blue road" an understood expression used to refer to particular roads?

Question

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.

Answer 1

As noted in wikipedia's Blue Highways article, blue highways is a term coined by William Least Heat Moon to refer to secondary roads, which appeared in blue in older Rand McNally road atlases. In the book, Mr. Least Heat Moon explains that these roads often are more scenic, more relaxed, more suitable for leisurely introspective trips. It's likely the sample sentence would be misunderstood or misinterpreted by most people as it isn't clear which of the two roads is meant.