Blue roads are non-thruway type roads.
The back roads if you will.
This is what we referred to them as back when I drove long distance motorcycle rallies.
We drove up north of Lockport and took 104 to 11 and then took 11 to get to Watertown on Sunday.
55 here in Cicero..............and dark.
However, it is 75 in North Port, FL.....................and also dark.