Engineering:Vienna Convention on Road Signs and Signals

Short description: 1968 international treaty

Convention on Road Signs

Signatories and ratifications as of April 2023   Signed   Ratified   Accession / succession   Uses the SADC Convention   Uses the SICA Convention
Signed	8 November 1968
Location	Vienna
Effective	6 June 1978
Condition	Ratification by 15 states
Signatories	35
Parties	71
Depositary	UN Secretary-General
Languages	Chinese, English, French, Russian and Spanish

The title page of the Vienna Convention on Road Signs and Signals

The Convention on Road Signs and Signals, commonly known as the Vienna Convention on Road Signs and Signals, is a multilateral treaty standardize the signing system for road traffic (road signs, traffic lights and road markings) in use internationally.

This convention was agreed upon by the United Nations Economic and Social Council at its Conference on Road Traffic in Vienna 7 October to 8 November 1968, was concluded in Vienna on 8 November 1968, and entered into force on 6 June 1978. This conference also produced the Vienna Convention on Road Traffic, which complements this legislation by standardising international traffic laws.

The convention revised and substantially extended the earlier 1949 Geneva Protocol on Road Signs and Signals, itself based in turn on the 1931 Geneva Convention concerning the Unification of Road Signals. Amendments, including new provisions regarding the legibility of signs, priority at roundabouts, and new signs to improve safety in tunnels were adopted in 2003.

Both the Vienna Convention and the Geneva Protocol were formed according to consensus on road traffic signs that evolved primarily in 20th century continental Western Europe. In order to make it as universal as possible, the convention allows some variations, for example danger warning signs can be triangular or square diamond in shape and road markings can be white or yellow. Though most UN members have not ratified the full treaty, the signs and legal principles enshrined in it form the basis of traffic law in a majority of places.

An alternative convention called the SADC-RTSM, provided by the Southern African Development Community (SADC), is used by ten countries in southern Africa. Many of the rules and principles of the SADC-RTSM are similar to those of the Vienna Convention.

In the United States, signs are based on the US Federal Highway Administration's Manual on Uniform Traffic Control Devices. Signs in the MUTCD are often more text-oriented, though some signs do use pictograms as well. Canada and Australia have road signs based substantially on the MUTCD. In South America, Ireland, several Asian countries (Cambodia, Japan, Thailand, Malaysia and Indonesia) and New Zealand, road signage is influenced by both the Vienna Convention and MUTCD. In Central America, road signs are heavily influenced by MUTCD and based on the Manual Centroamericano de Dispositivos Uniformes para el Control del Transito, a Central American Integration System (SICA) equivalent to the US MUTCD.

Rules

Road signs

In article 2 the convention classes all road signs into a number of categories (A – H):

• A: Danger warning signs
• B: Priority signs
• C: Prohibitory or restrictive signs
• D: Mandatory signs
• E: Special regulation signs
• F: Information, facilities, or service signs
• G: Direction, position, or indication sign
• H: Additional panels

The convention then lays out precise colours, sizes, and shapes for each of these classes of sign:

Class of sign	Shape	Ground	Border	Size	Symbol	Examples
Danger warning sign	Equilateral triangle	White or yellow	Red	0.9 m (large), 0.6 m (small)	Varies; Black or dark blue
	Diamond	Yellow	Black	0.6 m (large), 0.4 m (small)	Varies; Black or dark blue
Priority signs
Give Way sign	Inverted equilateral triangle	White or yellow	Red	0.9 m (large), 0.6 m (small)	None
Stop sign	Octagon	Red	White	0.9 m (large), 0.6 m (small)	Stop† written in white
	Circular	White or yellow	Red	0.9 m (large), 0.6 m (small)	Stop† written in black or dark blue inside red inverted triangle
Priority road	Diamond	White	Black	0.5 m (large), 0.35 m (small)	Yellow or orange square
End of priority road	Diamond	White	Black	0.5 m (large), 0.35 m (small)	Yellow or orange square with black or grey diagonal lines crossing the sign
Priority for oncoming traffic	Circular	White or yellow	Red	Unspecified	Black arrow indicating direction with priority, red arrow indicating direction without
Priority over oncoming traffic	Rectangle	Blue	None	Unspecified	White arrow indicating direction with priority, red arrow indicating direction without
Prohibitory signs
Standard prohibitory	Circular	White or yellow	Red	0.6 m (large), 0.4 m (small)	Varies; black or dark blue
Parking prohibited	Circular	Blue	Red	0.6 m (large), 0.2 m (small)	None
	Circular	White or yellow	Red	0.6 m (large), 0.2 m (small)	Initial letter or ideogram to denote parking; black or dark blue
Stopping prohibited	Circular	Blue	Red	0.6 m (large), 0.4 m (small)	None
End of prohibition	Circular	White or yellow	None	0.6 m (large), 0.4 m (small)	Black or grey diagonal line
Mandatory signs
Standard mandatory	Circular	Blue	None, white	0.6 m (large), 0.4 m (small), 0.3 m (very small)	Varies, white
	Circular	White or yellow	Red	0.6 m (large), 0.4 m (small), 0.3 m (very small)	Varies, black or dark blue
Special regulation signs
All signs	Rectangular	Blue	Unspecified	Unspecified	Varies, white
		Light	Unspecified	Unspecified	Varies, Black
Information, facilities or service signs
All signs	Unspecified	Blue or green	Unspecified	Unspecified	Varies, on white or yellow rectangle
Direction, position or indication signs
Informative signs	Rectangular, sometimes with arrowhead	Light	Unspecified	Unspecified	Varies, dark
		Dark	Unspecified	Unspecified	Varies, light
Motorways	Rectangular	Blue or green	Unspecified	Unspecified	Varies, white
Temporary	Rectangular	Yellow or orange	Unspecified	Unspecified	Varies, black
Additional panels
All panels	Unspecified	White, blue or yellow	Black, blue or red	Unspecified	Varies, black or dark blue
		Black, red or dark blue	White, blue or yellow	Unspecified	Varies, white, blue or yellow
Class of sign	Shape	Ground	Border	Size	Symbol	Examples

^† May be written in English or the national language

It also specifies the symbols and pictograms which may be used, and the orientations in which they may be used. When more than one is available, the same one must be used nationally. All signs, except for those that do not apply at night, must be reflective enough to be seen in darkness with headlights from a distance.

Road markings

The convention also specifies road markings. All such markings must be less than 6 mm high, with cat's eye reflectors no more than 15 mm above the road surface. The road markings shall be white or yellow.

The length and width of markings varies according to purpose, although no exact figures for size are stated; roads in built up areas should use a broken line for lane division, while continuous lines must only be used in special cases, such as reduced visibility or narrowed carriageways.

All words painted on the road surface should be either of place names, or of words recognisable in most languages, such as "Stop" or "Taxi".

Traffic lights

The Convention specifies the colours for traffic lights and their meanings, and places and purposes lights may be used for, like so:

Type	Shape	Colour		Position	Meaning
Non-flashing	Plain		Green	At intersection, entrance to tunnel or bridge	Proceed
			Amber	At intersection, level crossing, swing bridge, airport, fire station or ferry terminal	Stop if safe to do so
			Red	At intersection	Stop
			Red and amber	At intersection	Signal is about to change (usually to green)
	Arrow pointing left		Green	At intersection	Only traffic turning left may proceed
	Arrow pointing right		Green	At intersection	Only traffic turning right may proceed
	Arrow pointing upwards		Green	At intersection	Only traffic travelling straight ahead may proceed
	Arrow pointing downwards		Green	Above lane	Traffic may continue in lane
	Cross (×)		Red	Above lane	Traffic may not enter lane (lane closed)
	Arrow pointing diagonally downwards		Amber or white	Above lane	Lane closes shortly ahead, change lane in the direction of the arrow
Flashing	Plain		Double Red (alternating)	At level crossing, swing bridge, airport, fire station or ferry terminal	Stop
			Lunar white	At crossing	Proceed
			Amber (flashing)	Anywhere except intersection	Proceed with caution
			Amber (flashing)	At intersection	The priority is determined by 20px Priority Route or Yield signs or if none of the above regular right of way rule.

Red flashing lights may only be used at the locations specified above; any other use of the lights is in breach of the convention. Red lights must be placed on top when lights are stacked vertically, or on the side closest to oncoming traffic if stacked horizontally.

Contracting parties

The convention has 71 state parties and 35 signatories (including acceding members) as of October 2022: Albania, Armenia, Austria, Azerbaijan, Bahrain, Belarus, Belgium, Benin, Bosnia and Herzegovina, Brazil, Bulgaria, Burundi, Central African Republic, Chile, Costa Rica, Côte d'Ivoire, Croatia, Cuba, Cyprus, Czechia, Democratic Republic of the Congo, Denmark, Ecuador, Estonia, Finland, France, Georgia, Germany, Ghana, Greece, Guyana, Holy See, Hungary, India, Indonesia, Iran, Iraq, Italy, Kazakhstan, Kuwait, Kyrgyzstan, Latvia, Liberia, Liechtenstein, Lithuania, Luxembourg, North Macedonia, Madagascar, Mexico, Moldova, Mongolia, Montenegro, Morocco, Myanmar, Netherlands, Nigeria, Norway, Pakistan, Paraguay, the Philippines, Poland, Portugal, Romania, Russia, San Marino, Saudi Arabia, Senegal, Serbia, Seychelles, Sierra Leone, Slovakia, Slovenia, Spain, Sri Lanka, Suriname, Sweden, Switzerland, Tajikistan, Thailand, Tunisia, Turkmenistan, Uganda, Ukraine, United Arab Emirates, United Kingdom, Uzbekistan, Venezuela and Vietnam.

The only countries in Europe that are not parties to the convention are Andorra, Ireland, Iceland, Malta and Monaco.

Countries in Asia that are not parties to the convention are Afghanistan, Bangladesh, Malaysia, People's Republic of China (including Hong Kong and Macau), Republic of China (Taiwan), Israel, Japan, Jordan, Lebanon, North Korea, Oman, Palestine, Syria and Yemen. Cambodia, Laos, and South Korea are all signatories, but have yet to ratify the convention.

Other countries have not signed the convention; however, some have voluntarily adopted some Vienna convention signs.

See also

• Vienna Convention on Road Traffic
• Comparison of European road signs
• Comparison of MUTCD-influenced traffic signs
• Comparison of traffic signs in English-speaking countries

External links

• Ratifications — UN Treaty Collection
• Road Traffic and Road Signs and Signals Agreements and Conventions — United Nations Economic Commission for Europe
  • Full text of convention
  • Consolidated text of convention including diagrams
  • Amendments adopted in 2003