Road signs must be among the most extensively used symbols in the world. Wiki offers a remarkable simple and colourful catalogue for these signs, showing them for over two dozen countries. All in svg format too. But wether these are official digitizations is doubtful… (http://www.designwritings.com/tag/pictogram/#.WJsF6BDOhpY)
https://en.wikipedia.org/wiki/Category:Road_signs_by_country