We will, however, discuss them as a separate section for clarity. However, they are regulatory road signs so don’t necessarily need a category of their own. Many of the blue road signs can be found on motorways, although they are not limited to this type of road, and for this reason, some people will say there are 4 categories of road signs in Ireland by separating motorway signs out into their own category. A blue background with white symbols, numbers or lettering. A white background with a red border (circular, triangle and other shapes) with black symbols, letters or numbers within.Ģ. Regulatory Irish signs typically come in 2 formats.ġ. Regulatory road signs are also considered mandatory road signs that all drivers must obey.