OS Open Roads is a high-level view of the road network, from motorways to country lanes in Great Britain. The links represent an approximate central alignment of the road carriageway and include roads classified by the National or Local Highway authority (for example, A Roads) and unclassified roads which make up Great Britain’s road network. Attributes identify the roads that make up the Primary Route Network (PRN) and the Strategic Route Network (SRN). The SRN is made up of nationally significant roads used for the distribution of goods and services, and a network for the travelling public. They are known as Trunk Roads. Whilst the PRN is made up of roads used for transport on a regional or county level and include all roads which make up the SRN.