There are other immediate indicators when crossing the border: differences in the design of road signage and a change in road markings. The hard shoulder on non-motorway roads in Ireland is marked with a yellow, usually broken, line. The same marking in Northern Ireland is white and usually continuous. In Northern Ireland, roads use A (major) and B (minor) route prefixes, whereas Ireland's route prefixes are M (motorway) N (major, standing for "national") and R (minor, standing for "regional"). Road signs in both the Republic and those in Northern Ireland are mainly black/white/red triangles or circles (the same as the rest of the European Union). Signs have subtle differences in colouring and fonts. One notable exception to this is that hazard warning signs in the Republic are amber diamonds.