National Highways has updated the Manual of Contract Documents for Highway Works (MCHW) - the collection of standard specifications, technical details, and guidance that contractors must follow.
This vital set of documents underpins all UK motorway and trunk road construction contracts, National Highways said.
The national roads operator refreshed the MCHW to 'better align with current standard practices, making it clearer and more efficient for contractors'.
Key changes include:
- Templates to clearly outline the specific requirements for each contract
- Downloadable country-specific versions, including national requirements
- Content has been digitised to support machine readability, streamline contract production, and simplify future updates.
National Highways head of technical standards Steve Davy said: 'The updated manual not only reflects current best practice, it will also improve how highway projects are delivered by encouraging more consistency in the way work is carried out.
'We’re supporting the use of innovative materials including many low carbon material and construction methods, while maintaining our world class infrastructure standards.'
The updated MCHW applies to new contracts from the 30th September 2025. Existing contracts will continue to operate under the current specifications until completion.
Highways can reveal that among the standards now included in the MCHW is a new stone mastic asphalt specification.
Industry insiders suggest the new SMA standard is closer to the original design that was used widely in Germany and France, before it was imported t the UK more than two decades ago. That original design was changed by the Department for Transport in a move that has been often criticised since and now appears to have been reversed.
A National Highways spokesperson confirmed: 'Designers will now have the option to use a new stone mastic asphalt where appropriate. This new material has been developed based on extensive trials we’ve undertaken and designed specifically for England’s motorways and major A-roads. When used appropriately, this type of surface can offer improved durability and last longer.'
The new documents and supporting materials can be found here
