Amey Consulting designed and provided carbon consultancy services on the A590 dual carriageway resurfacing and reconstruction between M6 junction 36 and Brettargh Holt roundabout in Cumbria.
Amey’s carbon modelling experts worked with Highways England and contractors – Aggregate Industries, AE Yates and HW Martin – to measure the carbon benefits of the scheme. The works resulted in carbon reduction across three main areas: materials reduction and reuse, energy reduction, and transportation efficiencies.
In total the project reduced carbon by up to 43% compared to traditional solutions. Amey said, and reduced project costs from nearly £11m to just £8m.
Early collaboration between the client, the consulting engineer and the 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, Amey said. The model allowed for comparison of carbon reduction measures against a baseline ‘traditional’ solution.
Measures that 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. This reduced the need to transport materials to and from the site, eliminating approximately 6,000 lorry movements, saving 230 tonnes of CO2e.
This shortened construction programme also reduced road diversions and traffic management impacts in the area, Amey said. And the recycled road surface is more porous that a hot-rolled asphalt or concrete, resulting in less rolling noise from traffic.
Further carbon reductions were realised by using solar powered generators, lighting, signage, CCTV and catering facilities, along with the use of electric vehicles.
Highways England senior project manager Steve Mason said: “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 [construction works framework] partners [i.e. contractors], to add the efforts of AE Yates and Aggregate Industries are to be commended”.
Amey Consulting managing director Alex Gilbert said: “Key to success was using our carbon modelling expertise to understand how we can influence traditional solutions to reduce carbon output and cost for our client. This is an exciting step for highways industry as we believe this process has the potential to be built upon and replicated right across the UK”