Carriageway in-situ recycling
Where deterioration affects the structural layers of a road, carriageway in-situ recycling provides a durable and sustainable solution.
This technique is used mainly on rural roads, where traffic levels, site access and environmental considerations make it particularly effective.
By reusing existing materials, it strengthens the carriageway and extends its life without the need for full reconstruction.
Work process
The existing road surface and underlying layers are broken up using specialist machinery and processed on site. These materials are mixed with binding agents to create a recycled aggregate, which is relaid and compacted to form a new, strengthened road layer.
Reusing materials already in the carriageway reduces the need for new aggregates, limits waste and cuts down vehicle movements to and from the site.
Purpose
In-situ recycling addresses structural defects such as cracking, deformation and loss of strength, providing a stable foundation for future surfacing.
On rural roads, this approach is often followed by a surface treatment the following year, sealing the carriageway, improving skid resistance and protecting the recycled layers beneath.
Compared to traditional reconstruction, in-situ recycling is usually quicker and less disruptive, with shorter construction times and reduced impact on local communities.
Planning and prioritisation
Our programme of works is developed in line with the Highways Infrastructure Asset Management Plan and is informed by the latest road condition data.
This is collected through regular inspections, surveys and monitoring of the highway network, allowing us to prioritise the right treatment at the right time.
This ensures investment is targeted, risks are managed, and the long-term condition of the network is maintained in a cost-effective and sustainable way.
You can view our latest highways programme for details of current schemes, planned dates and updates.