Manual on Uniform Traffic Control Devices: Difference between revisions

Revision as of 19:47, 21 June 2025

Revision as of 19:48, 21 June 2025

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Government action to begin resolving the wide variety of signage that had cropped up did not occur until the late 1910s and early 1920s when groups from Indiana, Minnesota, and Wisconsin began surveying existing road signs in order to develop road signage standards. They reported their findings to the Mississippi Valley Association of Highway Departments, which adopted their suggestions in 1922 for the shapes to be used for road signs. These suggestions included the familiar circular railroad crossing sign and octagonal stop sign.<ref name="Johnson">{{cite magazine |last1 = Johnson |first1 = A.E. |editor1-last = Johnson |editor1-first = A.E. |title = A Story of Road Signing |magazine = American Association of State Highway Officials: A Story of the Beginning, Purposes, Growth, Activities, and Achievements of AASHO |date = 1965 |pages = 129–138 |publisher = American Association of State Highway Officials |___location = Washington, DC }}</ref>

In January 1925, [[Thomas Harris MacDonald]], chief of the federal [[Bureau of Public Roads]], published an article in which he argued that developing highway transportation in the United States to the "highest degree" would require five major innovations. Among them were "uniform markings and signs" and a "uniform [[color code]]".<ref name="MacDonald">{{cite journal |last1=MacDonald |first1=Thomas H. |title=The Urgent Necessity for Uniform Traffic Laws and Public Safety Devices |journal=American Highways |date=January 1925 |volume=4 |issue=1 |pages=5-7 |url=https://books.google.com/books?id=Z933iSTZIUUC&pg=RA7-PA7}} (At p. 7.)</ref>

In January 1927, the [[American Association of State Highway and Transportation Officials|American Association of State Highway Officials]] (AASHO) published the ''Manual and Specifications for the Manufacture, Display, and Erection of U.S. Standard Road Markers and Signs'' to set standards for traffic control devices used on rural roads.<ref name="NCHRPReport484">{{cite book |last1 = Hawkins |first1 = H. Gene |last2 = Parham |first2 = Angelia H. |last3 = Womack |first3 = Katie N. |title = NCHRP Report 484: Feasibility Study for an All-White Pavement Marking System |date = 2002 |publisher = Transportation Research Board |___location = Washington, DC |pages = A-1—A-7 |url = http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_484.pdf |access-date = August 10, 2020 |chapter = Appendix A: Evolution of U.S. Pavement Marking System }}</ref> Despite the title, this manual did not have any guidance on pavement markings.<ref name="NCHRPReport484"/> In the archaic [[American English]] of the 1920s, the term "road marker" was sometimes used to describe traffic control devices which modern speakers would now call "signs."<ref name="NCHRPReport484" /> In 1930, the National Conference on Street and Highway Safety (NCSHS) published the ''Manual on Street Traffic Signs, Signals, and Markings'', which set similar standards for urban settings, but also added specific guidance on traffic signals, pavement markings, and safety zones.<ref name="NCHRPReport484" /> Although the two manuals were quite similar, both organizations immediately recognized that the existence of two slightly different manuals was unnecessarily awkward, and in 1931 AASHO and NCSHS formed a Joint Committee to develop a uniform standard for both urban streets and rural roads. This standard was the MUTCD.<ref name="Johnson" />

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[[File:Mutcd warning signs 1971.jpg|thumb|left|170px|Warning signs introduced in the 1971 edition, combining both symbols and words]]

The 1971 edition of the MUTCD included several significant standards. The MUTCD imposed a consistent [[color code]] for [[road surface marking]]s by requiring all center lines dividing opposing traffic on two-way roads to be always painted in yellow (instead of white, which was to always demarcate lanes moving in the same direction),<ref name="NCHRPReport484" /><ref name="Section 3B-1">{{cite book |last1 = American Association of State Highway Officials |last2 = National Joint Committee on Traffic Control Devices |title = Manual on Uniform Traffic Control Devices for Streets and Highways |date = 1971 |publisher = Federal Highway Administration |___location = Washington, DC |page = 181 |chapter-url = https://books.google.com/books?id=gL9_gp8TUuMC&pg=PA181 |access-date = July 21, 2020 |chapter = Section 3B-1, Center Lines }}</ref> and also required that all highway guide signs (not just those on Interstate Highways) contain white text on a green background.<ref name="Section 2D-3">{{cite book |last1 = American Association of State Highway Officials |last2 = National Joint Committee on Traffic Control Devices |title = Manual on Uniform Traffic Control Devices for Streets and Highways |date = 1971 |publisher = Federal Highway Administration |___location = Washington, DC |page = 84 |chapter-url = https://books.google.com/books?id=gL9_gp8TUuMC&pg=PA84 |access-date = July 21, 2020 |chapter = Section 2D-3, Color, Reflectorization, and Illumination }}</ref>

Another major change, inspired by the Vienna Convention,<ref>{{cite news |title = Symbols to Replace Words on U.S. Traffic Signs |url = https://www.nytimes.com/1970/05/31/archives/symbols-to-replace-words-on-us-traffic-signs.html |work = The New York Times |date = May 31, 1970 |page = 58 }}</ref> was that the 1971 MUTCD expressed a preference for a transition to adoption of symbols on signs in lieu of words "as rapidly as public acceptance and other considerations permit."<ref name="Section 2A-13">{{cite book |last1 = American Association of State Highway Officials |last2 = National Joint Committee on Traffic Control Devices |title = Manual on Uniform Traffic Control Devices for Streets and Highways |date = 1971 |publisher = Federal Highway Administration |___location = Washington, DC |page = 16 |chapter-url = https://books.google.com/books?id=gL9_gp8TUuMC&pg=PA16 |access-date = July 21, 2020 |chapter = Section 2A-13, Symbols }}</ref> During what was then expected to be a transition period, the MUTCD allowed state highway departments to use optional explanatory word plaques with symbol signs and to continue using the previous standard word message signs in certain cases.<ref name="Section 2A-13" /> Robert Conner, the chief of the traffic control systems division of the Federal Highway Administration during the 1970s, believed that symbol signs were "usually more effective than words in situations where reaction time and comprehension are important."<ref name="Lindsey">{{cite news |last1 = Lindsey |first1 = Robert |title = Signs of Progress: Road Symbols Guiding Traffic |url = https://www.nytimes.com/1972/04/23/archives/signs-of-progress-road-symbols-guiding-traffic.html |access-date = August 19, 2020 |work = The New York Times |date = April 23, 1972 |page = S22 }}</ref> Conner was active in the Joint Committee and also represented the United States at international meetings on road traffic safety.<ref name="ConnerObituary">{{cite news |title = Robert Conner, Ex-FHA Official, Dies of Cancer |url = https://www.washingtonpost.com/archive/local/1984/12/01/robert-conner-ex-fha-official-dies-of-cancer/944fa379-9484-4f5d-9aa6-dbd7ef53f6b3/ |newspaper = The Washington Post |date = December 1, 1984 }}</ref> However, several American traffic safety experts were concerned that American drivers would not understand the Vienna Convention's unintuitive symbols, which is why the MUTCD allowed for explanatory word plaques.<ref name="Hebert">{{cite news |last1=Hebert |first1=Ray |title=New Traffic Signs Bloom as California Goes International |work=Los Angeles Times |date=January 30, 1972 |page=1}} Available via [[ProQuest]].</ref> Most of the repainting to the 1971 standard was done between 1971 and 1974, with a deadline of 1978 for the changeover of both the markings and signage.