Most road signs used by countries in the Americas are generally influenced by the Manual on Uniform Traffic Control Devices (MUTCD), first released in 1935, reflecting the influence of the United States throughout the region. Other non-American countries using road signs similar to the MUTCD include Australia, Indonesia, Ireland, Japan, Malaysia, and New Zealand. They are also the only countries listed here which drive on the left.
There are also a number of American signatories to the Vienna Convention on Road Signs and Signals: Brazil, Chile, Costa Rica, Cuba, Ecuador, Guyana, Mexico, and Venezuela. Of those, only Chile, Cuba, and Guyana have ratified the treaty; nonetheless, nearly all countries in the Americas use MUTCD-style yellow diamond warning signs.
It is also worth noting that, unlike in Europe, considerable variation within road sign designs can exist within nations, especially in multilingual areas. A notable example of this is Quebec, which uses a substantially different symbology than the rest of Canada.
The main differences between traffic signs influenced by the MUTCD relate to:
Graphic design and symbological detailsThe use of square-bordered or circular regulatory signsLocal languages (signs may be bilingual or trilingual)Most notable is the text on stop signs. Unlike in Europe, the text on stop signs in the Americas varies depending on language, and may be multilingual.Below is a table of the main languages used. Note that in non-English speaking countries, English is frequently included on signs near airports and tourist areas.
All countries, with the exception of the United States and Great Britain, use the metric system. Some countries mark this fact by using units on various signs.Brazil, Indonesia, Ireland, Mexico, Panama, Peru, and parts of Canada (British Columbia, Ontario, and Yukon) list units (km/h) on their maximum speed limit signs. In Canada and Ireland, this is a reflection of (somewhat) recent transitions from Imperial to metric.Advisory speed limit signs in most countries list units, although New Zealand does not. The US lists units in mph.Height, weight, and width restrictions are almost always accompanied by units (tonnes or metres); in the US, the short ton is used with no distinction from metric tonnes.Signs in Canada and Mexico near the US border often include both metric and Imperial units, to remind American drivers that they are entering metric countries. No such equivalent exists in the US.The US was, at one time, planning a transition to the metric system. The Metric Conversion Act of 1975 started the process, but it was halted in 1982. Nevertheless, the MUTCD specifies metric versions of speed limit signs. Furthermore, Interstate 19 in Arizona is partially signed in metric.Nearly all MUTCD-influenced warning signs are diamond-shaped and yellow; some warning signs may be fluorescent yellow-green in order to draw extra attention. There are a few exceptions to this:Pentagonal signs are used in school zones in the United States, Malaysia and many areas in Canada. But in the Philippines, pentagonal signs are used for pedestrian crossings.Canada and Japan use some pentagonal white-on-blue signs, although Canada is replacing these with black-on-fluorescent yellow-green signs of the same shape.Argentina employs European-style red-bordered triangular warning signs in certain instances where extra attention is required. The Philippines also uses this style for all warning signs.Warning signs may be text-only.Road works and construction
Most countries use orange or yellow diamond-shaped signs for construction zones. Australia and the Philippines use rectangular signs that fit into temporary casings.Prohibitory and restrictive signs are classified as regulatory signs, as per the MUTCD.Almost all prohibitory signs use a red circle with a slash. Restrictive signs typically use a red circle, as in Europe. Some may be seated on a rectangular white background.The original MUTCD prohibitory and restrictive signs were text-only (i.e. NO LEFT TURN). Some of these signs continue to be used in the US.The No Entry / Do Not Enter sign may or may not feature text. In some Latin American countries, an upwards-pointing arrow contained within a slashed red circle is used instead.The Latin American-style do not proceed straight sign may take a different meaning in countries with standard No Entry signs. Typically, it indicates an intersection where traffic cannot continue straight ahead, but where cross-traffic may enter the street from the right (or left). Thus, it is distinguished from a No Entry (for all vehicles) sign.Mandatory or permitted-action signs
The design of mandatory signs varies widely, since the MUTCD does not specify their use. Rather, the MUTCD's equivalent are classified as regulatory signs.Some countries use simple arrows with the text "ONLY" or its equivalent underneath. This is the MUTCD standard.Some countries use European-style white-on-blue circular signs. These are "Type A Mandatory Signs" as prescribed by the Vienna Convention.Some Latin American countries use red-bordered circular signs, in the same style as regulatory signs. These are "Type B Mandatory Signs" as prescribed by the Vienna Convention. In cases relating to particular types of vehicle traffic (e.g. buses), these signs are identical to some European prohibitory signs.Canada uses a unique style of mandatory sign that features a green circle.Highway and wayfinding signs
Most countries use white-on-green signs on highways and to indicate location, etc.The exact style of these signs varies widely, although many are influenced by the MUTCD standard.Chile, Ireland, Japan, and New Zealand use both white-on-green and white-on-blue guide signs, as does the Northwest Territories and Ontario in Canada.Malaysia uses both black-on-yellow and white-on-green guide signs.White-on-blue signs are sometimes used at airports and for rest areas.White-on-brown signs are sometimes used to indicate park areas.
