Roads in the United Kingdom

The United Kingdom has a well developed and extensive network of roads totalling about 262,300 miles (422,100 km). Road distances are shown in miles or yards and UK speed limits are indicated in miles per hour (mph) or by the use of the national speed limit (NSL) symbol. Some vehicle categories have various lower maximum limits enforced by speed limiters. A unified numbering system is in place for Great Britain, whilst in Northern Ireland, there is no available explanation for the allocation of road numbers.

The earliest specifically engineered roads were built during the prehistoric British Iron Age. The road network was expanded during the Roman occupation. Some of these roads still remain to this day. New roads were added in the Middle Ages and from the 17th century onwards. Whilst control has been transferred between local and central bodies, current management and development of the road network is shared between local authorities, the devolved administrations of Scotland, Wales and Northern Ireland, and National Highways in England. Certain aspects of the legal framework remain under the control of the United Kingdom parliament.

Although some roads have much older origins, the network was heavily developed from the 1950s to the mid-1990s to meet the demands of modern traffic. Construction of roads has become increasingly problematic with various opposition groups such as direct action campaigns and environmentalists. There are various ongoing and planned road building projects.

In the UK, road safety policy is part of transport policy. "Transport 2010; The 10 Year Plan" states that the basic principle is that "people travel safely and feel secure whether they are on foot or bicycle, in a car, on a train, or bus, at sea or on a plane".

The UK has a road network totalling about 262,300 miles (422,100 km) of paved roads—246,500 miles (396,700 km) in Great Britain (England, Scotland and Wales), and 15,800 miles (25,500 km) in Northern Ireland.

Responsibility for the road network differs between trunk and non-trunk routes. Trunk roads, which are the most important roads, are administered by National Highways in England, Transport Scotland in Scotland, the North and Mid Wales Trunk Road Agent, and South Wales Trunk Road Agent in Wales. England's 4,300 miles (6,920 km) of trunk roads account for 33% of all road travel and 50% of lorry travel. Scotland has 2,174 miles (3,499 km), about 7% of the total roads in Scotland, accounting for 35% of all road journeys and over 50% of lorry movements.

Wales has 1,000 miles (1,600 km) of trunk roads. In London, Transport for London is responsible for all trunk roads and other major roads, which are part of the Transport for London Road Network. All other roads are the responsibility of the relevant county council or unitary authority. In Northern Ireland, DfI Roads is responsible for all 5,592 miles (8,999 km) roads. The pan-UK total is 15,260 miles (24,560 km).

Whilst generally they are trunk roads, some motorways are the responsibility of local authorities, for example the M275.