America’s Byways® is the umbrella term for the collection of 150 distinct and diverse roads designated by the U.S. Secretary of Transportation. America’s Byways include the National Scenic Byways and All-American Roads. See the current list of dedicated byways and All-American roads here: Overview List of Scenic Byways and All-American Roads
Following the link to the official website of the Department of Transportation with a map and description of the current Scenic Byways in the United States: