The Vienna Convention for road signs and signals is a well known international treaty that was originally formed to standardise signing systems across the world. This concept of standardisation serves to allow people who constantly travel across the world to better understand the mandatory signs on roadways while in a new region. It came into force in June 1978 although discussions and proceedings towards designing and finalising the signs began in the 1960’s.
Categories targeted by the Convention
The Vienna Convention for road signs and signals was designed to target signs across roadways and tunnels. To make the process easier and have a better control over the design features, all road signs were further categorised into Danger Warning Signs, Priority Signs, Prohibitory or Restrictive Signs, Mandatory Signs, Information or Service Signs, Direction or Indication Sign, Additional Panels.
A few features of the standardised signs
The Convention served to lay out specific colours, sizes and shapes for each sign under these various classes.
Typically, as per the convention the following elements were introduced for road signs:
Danger warning signs were either formatted to be in a diamond or triangular shape in white or yellow with red or black borders.
Yield signs were formatted into inverted triangles in white or yellow with red borders.
Stop signs were formatted to be octagon or circular shaped in red, white or yellow with red borders or no border.
Different kinds of priority signs were formatted in either diamond, circular or rectangle shapes in white or yellow. Priority over oncoming traffic were standardised in blue.
Various kinds of prohibitory signs were formatted in circular shapes in white, yellow or blue with red or no border, depending on the kind of sign.
Standard mandatory signs were standardised to be circular in blue or white with red or no borders.
Informative signs were standardised to be rectangular shaped.
Motorways and temporary road signs were all standardised in rectangular shapes in blue, green, yellow or orange.
The language adopted is usually English, however a country’s national language is also permitted as per the convention.
The convention also specifies standards for road markings. The convention especially targets the use of broken or unbroken lines in lane divisions to show commuters if a road is a safe pathway or to signify reduced visibility in some places.
The convention specifies that words painted on the road surface should either be the names of places or words commonly understood by everyone – such as Stop, Exit, Taxi.
It is through the standardisation process at the convention that rules for traffic signals were also laid down. This is why most traffic signals around the world use common lights like Green to signify proceed, Amber to signify wait, Red to signify stop.
In some cases arrows in different colours may also be used