List of state routes in Arizona
The U.S. state of Arizona's State Routes are usually abbreviated as SR. History. The Arizona State Highway system was introduced on September 9, 1927, by the State Highway Commission (formed on August 11 of the same year). It incorporated the new federal aid system and also the U.S. Highway system. The 1927 plan included 27 state routes, most of which were simply dirt roads. Until 1942, the state route marker signs contained a Native American swastika that were used by Navajos, but were removed after the U.S.'s entry into World War II  against Nazi Germany which had a reversed swastika as its emblem and became strongly negatively associated with the Nazis. The modern system was introduced and adopted in the 1950s. Designations and nomenclatures. The Arizona Department of Transportation (ADOT) internally recognizes Interstate Highways, U.S. Highways and Arizona Highways as all being separate types of highway designations. State highways within Arizona are referred to as Arizona State Routes or State Routes, with the prefix "SR" being used for abbreviations. ADOT also recognizes seven different types of suffixed routes for the U.S. Highways and State Routes. The recognized suffixes consist of the following  with "(Number)" filling in for a numeric designation: U.S. Highways can also use the same suffixes listed above. Usually the suffixed routes are recognized by ADOT as U.S. Highways. For example, the Alternate route of U.S. Route 89 (US 89) is referred to as U.S. Route 89A (US 89A) instead of State Route 89A (SR 89A). The only exception to this rule is SR 93X, which is a suffixed route of US 93. Suffixed routes for Interstates are a different story. Although the suffixed routes are signed with Interstate green Business shields, they are recognized by ADOT as suffixed State  Routes. In the field, Interstate 10 business routes are signed as Interstate 10 Business Loop or Interstate 10 Business Spur, while they are referred to by ADOT as "State Business Route 10" (SR 10B) and "State Route 10 Spur" (SR 10 Spur). The same principle applies with business routes for all other Interstates in Arizona. Designations listed under Highway Logs and GIS data however, use the Arizona Transportation Information System (ATIS) nomenclature. The ATIS designation for a non-suffixed state route is "S (Number)". The number at the end is always three digits long. As such, all two digit routes  are referred to under the ATIS terminology as "S 0(Number)". SR 260 and SR 79 are known under ATIS nomenclature as "S 260" and "S 079" respectively. U.S. Highways replace the prefix "S" used by State Routes under the ATIS nomenclature with "U" while Interstate Highways use the prefix "I". Suffixed routes under ATIS always have the internally applied suffix between the prefix. State Business Route 79 under ATIS nomenclature is referred to as "SB079" and SR 93X is "SX093". State Routes. Unbuilt routes. Some routes listed here were eventually constructed using other route numbers. Arizona Parkways, Historic and Scenic  Roads. Currently, the Arizona Department of Transportation recognizes 26 state designated routes under the Parkways, Historic and Scenic Roads Program. Four are Historic Roads, 17 are Scenic Roads and five are Parkways.