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 that establishes an international standard for signing systems for road traffic, such as road signs, traffic lights and road markings. The Convention was agreed upon by the United Nations Economic and Social Council at its Conference on Road Traffic in Vienna, Austria from 7 October to 8 November 1968.

Source: Wikipedia — Vienna Convention on Road Signs and Signals (CC BY-SA 4.0)