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Highway Standards

We manage the Highway Standards and associated guidance to be used in Wales.

We identify the administrative and technical requirements for the planning, preparation, design and construction of highway works. We do this through the publication of standards and specifications to be used on the motorway and trunk road network in Wales.

The Highway Standards which apply to the Welsh motorway and trunk road network are contained in the Design Manual for Roads and Bridges (DMRB) (external site) and the Manual of Contract Documents for Highways Works (MCHW) (external site).

Both the DMRB and the MCHW are national standards applicable throughout the UK, produced by the Highways England in conjunction with the governments of Wales, Scotland and Northern Ireland.  

We publish associated guidance documents which support the UK Highway Standards defined in both the DMRB and the MCHW.  These associated guidance documents are divided into:

  • Interim Advice Notes (IANs) – provide supplementary guidance not contained within current standards
  • Procedure and Advice Guidance (PAG)
  • Street Works Guidance.