Welsh Government is responsible for all trunk roads in Wales, the maintenance and operation of which is delegated to Local Authority Trunk Road Agents.
In 2005/6, following a review of trunk road services in Wales, three Trunk Road Agencies were established to replace the previous eight. The 3 new Trunk Road Agencies covered North, Mid and South Wales respectively.
Following a further review, in April 2012 two new Agencies replaced the former three. The two new Agencies are: