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 or Vienna Convention for short) is a multilateral treaty that standardizes the design of traffic signs, traffic signals, and road markings in many countries around the world.
Background
The Vienna Convention's provisions were developed in the mid 20th century under United Nations sponsorship as an evolution of longstanding European signposting norms. Several more signs were subsequently added in a European Agreement and appendices and annexes thereof. The convention has been formally adopted by virtually all of Europe and a number of other countries abroad, albeit with subtle differences in implementation. Additional countries have adopted elements of the European sign system as part of national or regional standards.
Usage in OpenStreetMap
The Vienna Convention is influential within the OpenStreetMap community. Historically, a majority of mappers have come from Vienna Convention countries. This is especially true of the mappers who have shaped OSM's navigation mapping conventions over the years. For this reason, navigation-related tag proposals should generally consider affordances familiar to mappers in these countries, though not to the exclusion of other common paradigms.
A traffic sign is mapped as a 
node tagged traffic_sign=XY:Z, where XY is the country's ISO 3166 code and Z is the sign's alphanumeric designation in the relevant national traffic code. The sign numbers in the text of the Vienna Convention are not tagged directly; however, Vienna Convention model signs sometimes appear in global tagging documentation to avoid bias toward one country or another.
Some provisions in the Vienna Convention have given rise to keys and tags strictly tied to the sign but applied to the sign's referent rather than just the traffic_sign=* node. Most examples pertain to restrictions, such as motorroad=*, vehicle=*, and bicycle=use_sidepath (see Compulsory use of parallel way). At times, there has been confusion and debate about whether the tag corresponds to the sign per se or a particular national law that in turn corresponds to the sign. In non–Vienna Convention countries, tags specific to the convention either go unused or are applied to ostensibly analogous situations as a form of duck tagging, contributing to skunking.
Software support
Vienna Convention signs are available in a preset collection and style for JOSM.
Mapillary incorporates a variety of Vienna Convention signs into its traffic sign detection layer as miniature icons. These icons are available on GitHub in SVG format under the MIT license. KartaView maintains a similar icon set also under the MIT license.
See also
- Manual on Uniform Traffic Control Devices, a competing U.S. standard and the basis for sign standards in many non-Vienna Convention countries
External links
- Road Traffic and Road Signs and Signals Agreements and Conventions, United Nations Economic Commission for Europe
- Consolidated text of the Convention:
- Gallery of traffic signs in the Convention
- Status of treaty, United Nations Treaty Collection [1]