This file is in the public domain because it comes from the Utah Supplement to the Manual on Uniform Traffic Control Devices, sign number GS1-4a. The Utah Supplement states on 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 items owned by FHWA."

This shows how the SR-30 "state signed guide number" was signed along State Statutory Route 70 in the U.S. state of Utah from 1966 to 1977. It is from a 1966 resolution of the State Road Commission of Utah, available from the Utah Department of Transportation's website at [1]. Since it has no copyright notice and was published before 1989, it is likely that it cannot be copyrighted, but even if a copyright was claimed on the document as a whole, this drawing is ineligible for copyright, because it consists of a state route shield design (public domain by the terms of the federal Manual on Uniform Traffic Control Devices and federal law Title 23, Chapter I, Part 655) with a general drawing of a post, a rectangle with "SR. 70", and generic labels.