Example image of eyePlorer eyePlorer map for 'Dual carriageway': British English Central reservation Highway North American English Boulevard Single carriageway United Kingdom Pedestrian Roundabout A1 road (Great Britain) A38(M) motorway Motorway Traffic flow Built-up area (Highway Code) Republic of Ireland Roads in the United Kingdom N8 road (Ireland) Regional road High-quality dual carriageway M1 motorway (Republic of Ireland) M50 motorway (Ireland) N2 road (Ireland) Northern Ireland National secondary road National primary road Local government Shoulder (road) N11 road (Ireland) N18 road (Ireland) N25 road (Ireland) N20 road (Ireland) Ennis 2+2 road National Roads Authority 2007 December 7 Dromod Roosky 2+1 road Freeway Interstate Highway System Expressway United States Numbered Highways Dual carriageway At-grade intersection Manual on Uniform Traffic Control Devices United States Department of Transportation Lafayette, Indiana U.S. Route 52 400-series highways (Ontario)