A typical warning sign, as defined by the convention.
The Vienna Convention on Road Signs and Signals is an international treaty designed to increase road safety and aid international road traffic by standardising the signing system for road traffic (road signs, traffic lights and road markings) in use internationally.
Amendments, including new provisions regarding the legibility of signs, priority at roundabouts and new signs to improve safety in tunnels were adopted in 2003.
Yellow square and grey or black 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
Parking prohibitory
Circular
Blue
None
0.6 m (large), 0.2 m (small)
Varies
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
0.6 m (large), 0.4 m (small), 0.3 m (very small)
Varies, white
Circular
White
Red
0.6 m (large), 0.4 m (small), 0.3 m (very small)
Varies, black
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 or yellow
Black, blue or red
Unspecified
Varies, black or dark blue
Black or dark blue
White or yellow
Unspecified
Varies, white or yellow
† 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 which do not apply at night, must be reflective enough to been 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 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 carriage ways.
All words painted on the road surface should be either of place names, or of words which are recognisable in most languages, such as "Stop" or "Taxi".
Traffic lights
The Convention specifies the colours which may be used for traffic lights and their meanings, and places and purposes for which lights may be used, like so:
Type
Shape
Colour
Position
Meaning
Non-flashing
Plain
Green
At intersection
Proceed
Amber
At intersection, level crossing, swing bridge, airport, fire station or ferry terminal
Stop if possible
Red
At intersection
Stop
Red and amber
At intersection
Signal is about to change
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
Arrow pointing diagonally downwards
Amber or white
Above lane
Lane closes shortly ahead, change lane
Flashing
Plain
Double Red
At level crossing, swing bridge, airport, fire station or ferry terminal
Stop
Amber
Anywhere except intersection
Proceed with caution
Amber
At intersection
The priority is determined by Main Road [3] or Yield [4] signs
Lunar white
At crossing
Proceed
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
52 States at 30 June 2004: Albania, Austria, Bahrain, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Central African Republic, Chile, Côte d'Ivoire, Croatia, Cuba, Czech Republic, Democratic Republic of the Congo, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, India, Iran (Islamic Republic of), Iraq, Italy, Kazakhstan, Kuwait, Latvia, Lithuania, Luxembourg, Mongolia, Morocco, Norway, Pakistan, Philippines, Poland, Romania, Russian Federation, San Marino, Senegal, Serbia and Montenegro, Seychelles, Slovakia, Sweden, Switzerland, Tajikistan, The former Yugoslav Republic of Macedonia, Tunisia, Turkmenistan, Ukraine, Uzbekistan.