ファイル:Illinois 156.svg

This file is in the public domain because it comes from the Illinois Supplement to the National Manual on Uniform Traffic Control Devices, sign number M1-I100, which states on p. 1 that "the 2009 edition of the Illinois Manual on Uniform Traffic Control Devices (IMUTCD) consists of the December 2009 national Manual on Uniform Traffic Control Devices (MUTCD), including subsequent official revisions thereto, as amended by this Illinois Supplement to the MUTCD." The federal MUTCD states specifically on its page I-1 that: Any traffic control device design or application provision contained in this Manual shall be considered to be in the public domain. Traffic control devices contained in this Manual shall not be protected by a patent, trademark, or copyright, except for the Interstate Shield and any other items owned by FHWA. No provisions of the supplement amend this provision of the MUTCD.

30 in by 24 in (750 mm by 600 mm) Illinois Route shield, made to the specifications of the sign detail (sign M-I100). Uses the Roadgeek 2005 fonts. (United States law does not permit the copyrighting of typeface designs, and the fonts are meant to be copies of a U.S. Government-produced work anyway.) The outside border has a width of 1 (1/16 in) and a color of black so it shows up; in reality, signs have no outside border.