Designing ‘UK first’ carbon neutral road improvement project

Amey Consulting has designed the UK’s first carbon neutral road improvement project – an £8m Highways England carriageway reconstruction in Cumbria. Working alongside several contractors, Amey Consulting designed and provided carbon consultancy services on the A590 dual carriageway resurfacing and reconstruction between M6 junction 36 and Brettargh Holt roundabout

What did we do?

Amey Consulting’s carbon modelling experts worked with Highways England and contractors, including Aggregate Industries, A E Yates and HW Martin to measure the carbon benefits of the scheme. The works resulted in significant carbon reduction across three main areas; materials reduction and reuse, energy reduction and transportation efficiencies. 

Early collaboration between Amey Consulting, Highways England and contractors was key in developing the low-carbon solution as well as the bespoke carbon model used to calculate carbon emissions saved during the construction stage.

The model allowed for comparison of carbon reduction measures against a baseline ‘traditional’ solution. Key initiatives which reduced emissions during the construction stage included the ex-situ foam-mix recycling of existing road surface plainings, by producing a site batched cold recycled asphalt.

What was the impact?

In total the project reduced carbon by up to 43% compared to traditional solutions and saved almost £3m.

The foam-mix recycling on site significantly reduced the need to import and export materials to and from the site and erased approximately 6,000 HGV movements from the operation, saving 230 tonnes of CO2e. This shortened construction programme also reduced road diversions and traffic management impacts on the local community. Furthermore, the recycled road surface has greater porosity compared with a hot-rolled asphalt or concrete, helping to reduce rolling noise from vehicles.

In addition to the carbon benefits associated with the pavement solution, significant carbon reductions were also realised as a result of energy efficiency measures. The use of solar powered generators, lighting, signage, CCTV and catering facilities, along with the use of electric vehicles saved approximately 70 tonnes of CO2e.

The safety of road users was our key concern in the planning of this project. The installation of an ex situ recycling option and on-site asphalt plant gave us the opportunity to work 24/ 7 – removing the need for many thousands of deliveries but also allowing us to complete work near the motorway junction as quickly as possible and reduce any queuing associated with the roadworks. It was from this position that we tasked each contractor to help drive down the project’s carbon footprint. It was tremendous effort of collaboration between Highways England, Amey Consulting and our CWF partners, to add the efforts of AE Yates and Aggregate Industries are to be commended”. Steve Mason, Highways England’s Senior Project Manager