Manual on Uniform Traffic Control Devices: Difference between revisions

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In 1948, three years after [[World War II]] ended, the third edition of the MUTCD was released. The single most controversial and heavily debated issue during the early years of the MUTCD was the color of center lines on roads.<ref name="NCHRPReport484" /> This edition settled the long-running debate in favor of white, and also changed the standard color of stop signs from yellow to red.<ref name="NCHRPReport484" /> However, the 1948 MUTCD also allowed for two major exceptions to white center lines: yellow was recommended but not mandatory for double center lines on multi-lane highways and for center lines in no-passing zones.<ref name="NCHRPReport484" />

In 1949, the United Nations Conference on Road and Motor Transport launched a research project to develop a worldwide uniform scheme for highway signs.<ref name="Johnson" /> In 1951, the UN conducted experiments in the U.S. to compare the effectiveness of national traffic sign standards from around the world. Signs from six countries were placed along the road for test subjects to gauge their legibility at a distance.<ref>{{cite magazine |title = Tests of Highway Signs for United Nations |first1 = Charles R. |last1 = Waters |first2 = Gilbert W. |last2 = Treble |magazine = Traffic Engineering |date = July 1951 |page = 338 }}</ref> The test strips were located along [[Ohio State Route 104]] near [[Columbus, Ohio|Columbus]],<ref>{{cite news |title = Ohioans tell Europe to keep its signs |agency = United Press |work = [[Mansfield News Journal]] |date = March 27, 1951 |page = 11 |url = https://www.newspapers.com/clip/94492201/ |via = Newspapers.com }}</ref> [[U.S. Route 250 in Virginia|U.S. Route 250]] and [[Virginia State Route 53]] near [[Charlottesville, Virginia|Charlottesville]],<ref>{{cite news |title = Foreign Highway Signs Catch Eye |first = David |last = Barnett |work = [[The Richmond News Leader]] |___location = Richmond, Virginia |date = August 21, 1951 |at = p. 1-B |url = https://www.newspapers.com/clip/94493139/ |via = Newspapers.com }}</ref> [[Minnesota State Highway 101]] near [[Minneapolis]],<ref>{{cite news |title = U.N. Highway Signs Get Test |work = [[Minneapolis Star]] |date = March 27, 1951 |page = 9 |url = https://www.newspapers.com/clip/94493204/ |via = Newspapers.com }}</ref> and other roads in New York. [[France]], [[Chile]], [[Turkey]], [[India]], and [[Southern Rhodesia]] reciprocated by installing MUTCD signs on their roads.<ref name="Air Bulletin">{{cite magazine |title = U.N. Tests New Road Signs in U.S. |magazine = Air Bulletin: World Affairs |volume=1 |issue=7 |publisher = [[United States Information Service]] |date = May 7, 1951 |pages = 4–5 |url = https://books.google.com/books?id=YPGdar6V4dsC&pg=RA1-PP73 |via = Google Books }}</ref> In the U.S., the experiments attracted unexpected controversy and curious onlookers who posed a hazard.<ref>{{cite news |title = Foreign Road Sign Test Arouses Some Criticism |agency = Associated Press |work = [[The Independent (Massillon)|The Independent]] |___location = Massillon, Ohio |date = March 27, 1951 |page = 12 |url = https://www.newspapers.com/clip/94492382/ |via = Newspapers.com }}</ref><ref>{{cite news |title = Road Sign Test for UN Given Up |agency = Associated Press |work = [[Daily Press (Virginia)|Daily Press]] |___location = Newport News, Virginia |date = March 30, 1951 |page = 13 |url = https://www.newspapers.com/clip/94492425/ |via = Newspapers.com }}</ref> By September 1951, the experts working on the project were in favor of the American proposals for stop signs (at the time, black "STOP" text on a yellow octagon), "cross road", "left or right curve", and "intersection", but were still struggling to reach consensus on symbols for "narrow road", "bumpy or uneven surface", and "steep hill".<ref name="Hoffman">{{cite news |last1=Hoffman |first1=Michael L. |title=U.N. Nearer Accord on Traffic Signs: Standard Markers of U.S. May Serve as a Basis For World System |url=https://www.nytimes.com/1951/09/23/archives/un-nearer-accord-on-traffic-signs-standard-markers-of-us-may-serve.html |access-date=July 8, 2023 |work=The New York Times |date=September 23, 1951 |page=125}}</ref>

In 1953, after cooperating with the UN conference's initial experiments, the United States declined to sign or ratify the UN's then-proposed protocol for a worldwide system of uniform road signs.<ref name="Johnson" /> There were two major reasons behind this decision.<ref name="Johnson" /> First, most U.S. roads and streets were (and still are) under state jurisdiction.<ref name="Johnson" /><ref name="Air Bulletin" /> Second, the United States was developing modern [[controlled-access highway]]s at the time (culminating in the creation of the [[Interstate Highway System]] in 1956), and the novel problems presented by such new high-speed highways required rapid innovations in road signing and marking "that would definitely be impaired by adherence to any international code".<ref name="Johnson" /> Despite the Americans' withdrawal from the research project, the experiments eventually resulted in the Vienna Convention on Road Signs and Signals of 1968.