It seems as though I’ve had to look this up over and over. Finally, here are all the definitions, for the first time ever, together:
§28-101, 52. “Street” or “highway” means the entire width between the boundary lines of every way if a part of the way is open to the use of the public for purposes of vehicular travel.
§28-601, 22. “Roadway” means that portion of a highway that is improved, designed or ordinarily used for vehicular travel, exclusive of the berm or shoulder. If a highway includes two or more separate roadways, roadway refers to any such roadway separately but not to all such roadways collectively.
§28-601, 24. “Sidewalk” means that portion of a street that is between the curb lines or the lateral lines of a roadway and the adjacent property lines and that is intended for the use of pedestrians.
So a sidewalk is part of the street/highway. The roadway is a very specific, limited place; and doesn’t include the shoulder. There is no specific definition of the term shoulder; though we can say for sure is it’s not part of the roadway.
Bicyclists are traffic:
§28-601, 28 “Traffic” means pedestrians, ridden or herded animals, vehicles and other conveyances either singly or together while using a highway for purposes of travel.
Note that the MUTCD is incorporated into ARS. Here are the definitions as above; they seem to be entirely consistent (yay). From MUTCD 2009 revision 2; Section 1A.13 Definitions of Headings, Words, and Phrases in this Manual:
Street—see Highway; Highway—a general term for denoting a public way for purposes of vehicular travel, including the entire area within the right-of-way.
Road—see Roadway; Roadway—that portion of a highway improved, designed, or ordinarily used for vehicular travel and parking lanes, but exclusive of the sidewalk, berm, or shoulder even though such sidewalk, berm, or shoulder is used by persons riding bicycles or other human-powered vehicles.
Sidewalk—that portion of a street between the curb line, or the lateral line of a roadway, and the adjacent property line or on easements of private property that is paved or improved and intended for use by pedestrians.
Here are some more definitions related to bicycles; most of these definitions, with the exception of bicycle, are not in ARS:
Bicycle—a pedal-powered vehicle upon which the human operator sits.
Bicycle Facilities—a general term denoting improvements and provisions that accommodate or encourage bicycling, including parking and storage facilities, and shared roadways not specifically defined for bicycle use.
Bicycle Lane—a portion of a roadway that has been designated for preferential or exclusive use by bicyclists by pavement markings and, if used, signs.
Bikeway—a generic term for any road, street, path, or way that in some manner is specifically designated for bicycle travel, regardless of whether such facilities are designated for the exclusive use of bicycles or are to be shared with other transportation modes.
Designated Bicycle Route—a system of bikeways designated by the jurisdiction having authority with appropriate directional and informational route signs, with or without specific bicycle route numbers.
Shared Roadway—a roadway that is officially designated and marked as a bicycle route, but which is open to motor vehicle travel and upon which no bicycle lane is designated.
Shared-Use Path—a bikeway outside the traveled way and physically separated from motorized vehicular traffic by an open space or barrier and either within the highway right-of-way or within an independent alignment. Shared-use paths are also used by pedestrians (including skaters, users of manual and motorized wheelchairs, and joggers) and other authorized motorized and non-motorized users.
AFAIK, there’s not legal definition of a freeway, but in common usage, it begins with a controlled access highway:
§28-601, 2. “Controlled access highway” means a highway, street or roadway to or from which owners or occupants of abutting lands and other persons have no legal right of access except at such points only and in the manner determined by the public authority that has jurisdiction over the highway, street or roadway.
Freeways are often taken to mean a fully controlled-access highway. Where fully refers to no intersections, and all entering/leaving the highway is done through entrance/exit ramps only.
AASHTO Guide to Bicycle Facilities
The following definitions are excerpted from the list of definitions appearing in the AASHTO Guide to Bicycle Facilities, 4th Edition (2012). The definition of Shared Use Path differs slightly from that in the MUTCD:
Shared Use Path — A bikeway physically separated from motor vehicle traffic by an open space or barrier and either within the highway right-of-way or within an independent right-of-way. Shared use paths may also be used by pedestrians, skaters, wheelchair users, joggers, and other non-motorized users. Most shared use paths are designed for tow-way travel.
Shoulder — The portion of the roadway contiguous with the traveled way that accommodates stopped vehicles, emergency use, and lateral support of the subbase, base, and surface courses. Shoulders, where paved, are often used by bicyclists.
I included the shoulder definition specifically because I can’t find it elsewhere; though referred to, it’s not defined in the MUTCD, or in ARS.