A63 road in the context of "Divided highway"

A trunk road is a major highway with a specific legal classification in some jurisdictions, notably the United Kingdom, Sweden and formerly Ireland. Trunk roads are planned and managed at the national level, distinguishing them from non-trunk roads which are managed by local authorities. Trunk roads are important routes usually connecting two or more cities, ports, airports and other places, which is the recommended route for long-distance and freight traffic. Many trunk roads have segregated lanes in a dual carriageway, or are of motorway standard.

The term trunk road, or trunk highway, is sometimes used more generically to refer to other categories of major highway.

A dual carriageway (BrE) or a divided highway (AmE) is a class of highway with carriageways for traffic travelling in opposite directions separated by a central reservation (BrE) or median (AmE). Roads with two or more carriageways which are designed to higher standards with controlled access are generally classed as motorways, freeways, etc., rather than dual carriageways.

A road without a central reservation is known as a single carriageway regardless of how many lanes there are. Dual carriageways have improved road traffic safety over the years and over single carriageways and typically have higher speed limits as a result. In some places, express lanes and local or collector lanes are used within a local-express-lane system to provide more capacity and to smooth out traffic flows for longer-distance travel.