English: 16x16 U.S. route shield approximated to the 1948 standards, modified to use the 1926 font set. (The standards are believed to be identical except for the fonts.
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.