The Vienna Convention on Road Signs and Signals opened for signature in 1968.
The treaty was adopted in Vienna on 8 November 1968, alongside a related convention on road traffic. Its purpose was to standardise traffic signs, road markings and signal principles so that international travel would be easier and safer.
The convention classifies signs by function and establishes broadly shared designs. Warning signs, regulatory signs and informatory signs are treated as distinct groups, although countries may retain national variations in symbols, wording and colours. The agreement therefore creates a common framework rather than one identical sign catalogue.
The convention followed earlier European efforts to harmonise road traffic rules. Its influence is especially visible across Europe and in many other countries, but not every nation applies every provision in exactly the same way. Domestic law remains decisive for drivers using a particular road.