Editing U.S. Route shield (section)

===1948 version===
[[File:Old US 6 US 202 shields.jpg|thumb|right|1948-style shields for US&nbsp;6 and US&nbsp;202 in Connecticut, with the state name abbreviated]]

The 1948 edition of the MUTCD introduced the first change to the U.S. Route shield since its appearance in the 1927 AASHO manual.  The old block typefaces were replaced by the modern [[Highway Gothic|FHWA Series]] typefaces, which had since been developed. The shield shape and size, letter height, and layout was otherwise identical to the prior version.<ref name="1948-MUTCD">{{cite book |author1 = American Association of State Highway Officials |author2 = Institute of Traffic Engineers |author3 = National Conference on Street and Highway Safety |location = Washington, D.C. |publisher = Bureau of Public Roads |title = Manual on Uniform Traffic Control Devices For Streets and Highways |year = 1948 |edition = 1948 |url = https://ceprofs.civil.tamu.edu/ghawkins/1948-MUTCD.htm |via = Texas A&M University |access-date = June 5, 2010 |oclc = 5166173 }}</ref>

The 1948 MUTCD also included a specification for an "oversize" route marker, intended for major highway junctions in rural areas, as well as for special emphasis in urban areas. This shield was printed on a square blank, {{convert|24|x|24|in|cm}}, twice the size of the cutout shield. This version of the shield was much simplified, with the crossbar, state name, and "U&nbsp;S" omitted. The portion of the blank falling outside of the shield outline was white.<ref name="1948-MUTCD"/>