Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In 1926, Arkansas renumbered its highways into a more traditional format. The system to be replaced was established in 1924 as Arkansas' first comprehensive highway plan. Roads were designated as "primary federal aid roads", "secondary federal aid roads", or "connecting state roads". The Arkansas State Highway Commission implemented the system of United States Numbered Highways also around 1926, and thus Arkansas decided to number its highways instead of using the "letter-nn" format. This resulted in the first true numbering of state highways in Arkansas.