Editing U.S. Route shield (section)

===1961 version===
[[File:Southbound beginning US 277.jpg|thumb|right|Modern (left) and 1961 (right) shields in Newcastle, Oklahoma; the older shield uses the FHWA Series A typeface, which has since been discontinued.]]
The next version of the MUTCD, the 1961 edition, made further alterations to the U.S. route shield. The {{convert|16|x|16|in|cm|adj=on}} cutout shield was retained, but its use was restricted to [[reassurance marker]] contexts. Turn, junction, and trailblazer shields were to always use the oversize marker, which had been modified to use a black, rather than white, background surrounding the shield.<ref name="1961-MUTCD">{{cite book |author1 = National Joint Committee on Uniform Traffic Control Devices |author2 = American Association of State Highway Officials |title = Manual on Uniform Traffic Control Devices for Streets and Highways |year = 1961 |edition = 1961 |location = Washington, D.C. |publisher = Bureau of Public Roads |oclc = 35841771 |url = http://www.trafficsign.us/1961mutcd.html |via = TrafficSign.us |access-date = June 5, 2010 }}</ref>

A supplemental AASHO publication outlining signage and pavement markings on the nascent [[Interstate Highway System]], also published in 1961, included a variant of the shield intended for freeway use (such as for U.S. routes [[concurrency (road)|running concurrently]] with Interstates). This shield, the same size as the oversize marker, was a simplified cutout shield, containing only the outer border, "U&nbsp;S", and the route marker. Unlike the federally specified shields up to this point, this specification included a wider version, {{convert|28|x|24|in|cm}} for three-digit routes. This version of the shield is still used in California, the only state to still specify a cutout shield.<ref name="aasho-manual-1961">{{cite book |author1 = American Association of State Highway Officials |author2 = Bureau of Public Roads |title = Manual for Signing and Pavement for the National System of Interstate and Defense Highways |year = 1961 |edition = 1961 |location = Washington, D.C. |publisher = 	American Association of State Highway Officials |oclc = 43890586 }}</ref>