A scenic road is a general term that is often used to apply to several types of roadways offering visual, historic, and cultural significance. A scenic road is also used as a specific term to describe a certain type of roadway.
The Arizona Department of Transportation oversees the designating and planning of of scenic roads. There are 5 types of scenic roads in the state:

These roads include a roadway (or segment of a roadway) that offers a memorable visual impression, is free of visual encroachment, and forms a harmonious composite of visual patterns. Scenic roads are the most commonly designated type In Arizona; there are 18 roads designated as Scenic Roads. Some of the more popular Scenic Roads include:

These roads include a roadway (or segment of a roadway) that offer historical importance to the cultural heritage of the state, nation, or region, contribute to a historical area or exploration/settlement of Arizona, be easily accessible, and uniqueness. This type of scenic road is far less common than designated Scenic Roads. In this state; there are presently two Historic Roads:

Parkways include a roadway (or segment of a roadway) that meets scenic or historic road criteria, have a one-mile minimum distance between access roads, allow visitor facilities/interpretive areas, and offers controlled access and adjacent development. This type of scenic road, similar to Historic Roads, is far less common than designated Scenic Roads. In this state; there are presently 2 Parkways:

National Scenic Byways include a roadway (or segment of a roadway) that has multi-state significance and posses one or more of the following qualities: scenic, historic, recreational, cultural, archaeological, or natural. They must be a currently designated State scenic road, and contain no gaps in continuity, accommodate bicycles and pedestrians, and have a completed Corridor Management Plan, In Arizona, there are 3 National Scenic Byways:

All-American Roads include a roadway (or segment of a roadway) that has national significance and posses a multiple of the following qualities: scenic, historic, recreational, cultural, archaeological, or natural. They must be a currently designated State scenic road, and contain no gaps in continuity, accommodate bicycles, pedestrians and scenic pullouts, have a completed and implemented Corridor Management Plan., Lastly, the road must be considered a destination. In Arizona, there are 2 All-American Roads: