Dual carriageway in the context of "A30 road"

The A1, also known as the Great North Road, is the longest numbered road in the United Kingdom, at 410 miles (660 km). It connects London, the capital of England, with Edinburgh, the capital of Scotland. The numbering system for A-roads, devised in the early 1920s, was based around patterns of roads radiating from two hubs at London and Edinburgh. The first number in the system, A1, was given to the most important part of that system: the road from London to Edinburgh, joining the two central points of the system and linking two of the UK's mainland capital cities. It passes through or near north London, Hatfield, Stevenage, Baldock, Biggleswade, Peterborough, Stamford, Grantham, Newark-on-Trent, Retford, Doncaster, Pontefract, York, Wetherby, Ripon, Darlington, Durham, Gateshead, Newcastle upon Tyne, Morpeth, Alnwick, Berwick-upon-Tweed, Dunbar, Haddington, Musselburgh, and east Edinburgh.

It was designated by the Ministry of Transport in 1921, and for much of its route it followed various branches of the historic Great North Road, the main deviation being between Boroughbridge and Darlington. The course of the A1 has changed where towns or villages have been bypassed, and where new alignments have taken a slightly different route. Between the North Circular Road in London and Morpeth in Northumberland, the road is a dual carriageway, several sections of which have been upgraded to motorway standard and designated A1(M). Between the M25 (near London) and the A720 (near Edinburgh) the road is part of the unsigned Euroroute E15 from Inverness to Algeciras.

The Chesapeake Bay Bridge–Tunnel (CBBT, officially the Lucius J. Kellam Jr. Bridge–Tunnel) is a 17.6-mile (28.3 km) bridge–tunnel that crosses the mouth of the Chesapeake Bay between Delmarva and Hampton Roads in the U.S. commonwealth of Virginia. It opened in 1964, replacing ferries that had operated since the 1930s. A major project to dualize its bridges was completed in 1999, and in 2017 a similar project was started to dualize one of its tunnels.

With 12 miles (19 km) of bridges and two one-mile-long (1.6 km) tunnels, the CBBT is one of only 14 bridge–tunnel systems in the world and one of three in both Hampton Roads and the United States. It carries US 13, which saves motorists roughly 95 miles (153 km) and 1+1⁄2 hours on trips between Hampton Roads and the Delaware Valley and points north compared with other routes through the Washington–Baltimore Metropolitan Area. As of January 2021, over 140 million vehicles have crossed the CBBT.

A median strip, central reservation, roadway median, or traffic median is the reserved area that separates opposing lanes of traffic on divided roadways such as divided highways, dual carriageways, freeways, and motorways. The term also applies to divided roadways other than highways, including some major streets in urban or suburban areas. The reserved area may simply be paved, but commonly it is adapted to other functions; for example, it may accommodate decorative landscaping, trees, a median barrier, or railway, rapid transit, light rail, or streetcar lines.

The M54 is a 23-mile-long (37 km) east-west motorway in the counties of Shropshire and Staffordshire, England. It is also referred to as the Telford motorway, after the road's primary westbound destination, the town of Telford. It cost £65 million to construct, and is two-lane dual carriageway for the majority of its length, with sections of three-lane.

The M54 spur connects the M6 motorway near Essington, Staffordshire with the A5 trunk road at Wellington, Shropshire. The motorway forms part of the strategic route to North Wales, roughly following the path of the Roman Watling Street and the A5 north-westwards, towards the port of Holyhead. It is the only motorway in Shropshire, and forms a vital part of the county's road network. In 2007, the motorway handled an annual average daily traffic of between 50,300 (J2–3) and 41,800 (J4–5) vehicles.

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.

The Edinburgh City Bypass, designated as A720, is one of the most important trunk roads in Scotland. Circling around the south of Edinburgh, as the equivalent of a ring road for the coastal city, it links together the A1 towards north-east England, the A702 towards north-west England, the M8 through the Central Belt towards Glasgow, the A7 through south-east Scotland and north-west England as well as the A8 leading to the M9 for Stirling and the Queensferry Crossing.

The road is dual carriageway standard throughout, including emergency laybys and hard shoulders in areas. The road is classed as a special road in legal terms. Every motorway in the UK is termed a special road in that specific regulations govern its use. Not every special road is classed as a motorway and this bypass is one of those roads.

The A13, also officially known as Khasab–Tibat Road (Arabic: طريق خصب - تيبات) and formerly designated as Route 2 (Arabic: طريق ٢), is an arterial road in the Sultanate of Oman specifically in the Musandam exclave. The main road runs from the border of the United Arab Emirates to the regional capital Khasab. The A13 starts with only one lane on each side until it merges into a dual carriageway right after entering the city of Khasab and almost always runs along the coast of the Persian Gulf.