Exclusive research by the Asphalt Industry Alliance (AIA) and LCRIG in the annual ALARM survey has uncovered a wide gap between action and intention when it comes to decarbonising local road maintenance.
The results of a previously unreleased joint LCRIG/AIA section of this year's survey found that 90% of local authorities in England and Wales have a net zero pledge – with more than half of these giving 2030 as their target date.
However, only 11% reported that they had updated their highway asset management plan to include net zero principles and targets and only 6% had a target to reduce carbon from road surfacing materials.
Revealing the results at the LCRIG Strictly Highways conference this week, chair of the AIA David Giles (pictured) also highlighted 'another disconnect – between policy ambitions and the reality of managing the highway asset on a limited budget' when it came to low carbon materials.
He revealed that while warm mix asphalts (WMA) are on the specification list at the majority of local authorities in England, industry figures show that only around 5% of all asphalt manufactured is produced as warm mix, despite evidence that it can reduce the CO2 associated with asphalt production by up to 15%.
National Highways has adopted WMA as standard for the strategic network 'but take-up at a local authority level has been much slower,' Mr Giles said.
He added: 'A key part of the decarbonisation story is reducing the number of maintenance interventions by specifying more durable materials and 72% of those responding to the net zero asphalt ALARM section reported that they actively select materials with longer life.
'It is clear that enhancing the durability of materials reduces the number of maintenance interventions and minimises whole-life carbon emissions. Polymer modified bitumens, for example, are well known for extending the life of the asphalt and can also include recycled and biogenic content to help further reduce embodied CO2.'
Mr Giles accepted that there could be a conflict in the mind of engineers, with some specifying traditional hot rolled asphalt precisely because they thought it was more durable and so lower carbon over its lifetime.
The path to net zero section in ALARM also asked which net zero training areas would be most beneficial to help authorities achieve their decarbonisation aims.
The area that was ranked as the most important was 'materials innovation and how to select materials based on carbon impact'.
'The good news is we’ll be showcasing examples of this at our Sharing Best Practice event next month and you can find out more about that on the AIA website,' Mr Giles said.
