Special Committee on U.S. Route Numbering (May 19, 2012). "Report to SCOH"(PDF) (Report). Washington, DC: American Association of State Highway and Transportation Officials. p. 2. Archived from the original(PDF) on June 3, 2019. Retrieved April 9, 2017.
Special Committee on U.S. Route Numbering (May 19, 2012). "Report to SCOH"(PDF) (Report). Washington, DC: American Association of State Highway and Transportation Officials. p. 2. Archived from the original(PDF) on June 3, 2019. Retrieved April 9, 2017.