Trunk road

From Academic Kids

A trunk road, trunk highway, or strategic road is a major road, usually connecting one or more cities, ports, airports etc, which is the recommended route for long-distance and freight traffic. Many trunk roads have segregated lanes, or are motorway standard.


United Kingdom

In the United Kingdom, Trunk Roads were first defined in the Trunk Roads Act of 1936. Of the UK's road network, 30 of the nation's major roads were classed as Trunk Roads and the Minister of Transport took direct control, under the auspices of the Highways Agency, of the roads and the bridges across them (though Scotland, Wales and Northern Ireland now have responsibility for their own roads). At that time, there was 4,500 miles of road classified as Trunk Roads.

Since then, many roads have been extended and 'trunked'. Virtually all UK motorways are classed as Trunk Roads, and as of 2004, England has 10,458 km of Trunk Roads.

Curiosities and facts about Trunk Roads

Trunk roads are part of a hierarchy of sub-categories of 'A' roads. All trunk roads are "primary routes", the category of recommended roads for long distance and freight transport, but only the busiest primary routes are trunk roads, the difference being that trunk roads are maintained by the Highways Agency rather than the local councils. Primary routes are identified by their road signs, which feature white text on a green background. Trunk roads, like other 'A' roads, can either be single- or dual-carriageway.

A trunk road which has been partially upgraded to motorway standard can sometimes retain its original "A" number but with an "M" in brackets to denote that motorway regulations apply on it. This is common on Primary Routes which are slowly being converted to motorway standard, but have not yet been completed. Good examples of this are the A1(M) in England, and the A74(M) in Scotland.

It is possible for roads to become 'de-trunked' to County 'A' Roads, for example when superseded by a motorway following a similar route. When a road is 'detrunked' it is often not visible to the normal user when it retains its numbers. In some places however, the road number will change an will usually be signposted in the style "B000, was A00", although repeated changes can lead to such nonsense as "A5, was A5" (between St Albans and Redbourn).


In Ireland some roads were classified under an old British system as Trunk routes, and had route numbers prefixed by "T". Another old designation was Link, or "L", road. Although a number of old road signs using these designations may still be encountered, Ireland has long since adopted a newer classification scheme of National Primary and Secondary Routes ("N" roads), Regional roads ("R" roads), and local roads (administratively referred to by "L"-prefixed numbers, though these numbers are not shown on signs).

United States

The U.S. highway and Interstate highway systems can be considered trunk highways of the United States, although actual construction and maintenance is delegated to individual U.S. states (funding is apportioned as well). Each state maintains its own trunk highway system, incorporating state, U.S., and Interstate routes.


China has begun development of the National Trunk Highway System (NTHS), which will create many east-west and north-south highways, plus seven radials heading out of the capital, Beijing.

See also


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