This section sets out the principles governing the use of road numbers and destinations on directional traffic signs.

The design and application of directional signing shall accord with the requirements of the Traffic Signs Regulations and General Directions (TSRGD) and relevant Department for Transport guidance.

Direction signage is structured to provide clear and consistent guidance to motorists through the use of a defined hierarchy of routes and destinations.

The signing system uses colour coding to indicate the classification and relative importance of routes, assisting drivers in following appropriate networks.

The principal colour conventions are as follows:

Motorways – Blue background

Primary Routes – Green background, or green panels on white signs

Non-Primary Routes ('A', 'B', 'C' and unclassified roads) – White background

Direction signs may incorporate coloured panels (“patching”) to indicate the status of connecting routes along which destinations can be reached.

The following routes form the Primary Route Network within County Durham and are signed using green backgrounds or green panels:

A19 – Entire length

A66 – Entire length

A67 – Within Barnard Castle (between A688 and B6277)

A68 – Entire length

A167 – From Aycliffe Interchange to Northlands Roundabout

A688 – From A181 Running Waters to Barnard Castle

A689 – From County Boundary at Wynyard to Coundon Gate Roundabout

A690 – From County Boundary at Sunderland to Neville’s Cross

A691 – From A690 Millburngate Roundabout to A692 Leadgate

A692 – From Castleside to County Boundary at Burnopfield

A693 – From A1(M) Junction 63 to A692 Leadgate

A1018 – Entire length

A6072 – From Shildon to Bishop Auckland

A6072 – From Shildon to Bishop Auckland