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Climate change Blog - FHRG's new carbon reporting guidance

Proving Services' Simon Wilson takes us through the Future Highways Research Group's new carbon reporting guidance for highways and infrastructure.


The FHRG and ADEPT have released the Carbon Calculation & Accounting Standard (CCAS) for the highways sector. The CCAS document represents the culmination of a four-year research programme.

Our initial market assessment of carbon reporting in the UK highways sector revealed a highly fragmented landscape of carbon calculators, carbon emissions factors, and competing reporting standards and philosophies. Creating, straightforward, relevant, and useful carbon accounting guidance was, therefore, challenging. The diversity of operating models, local authority readiness, and complex supply chains, combined with the evolving carbon reporting standards and the changing priorities of local authorities, greatly amplified the complexity of the task.

Resources within local highways authorities are limited and precious, so the design goals were simple: create guidance that enables LHAs to implement low-overhead, transparent, and repeatable processes using internal resources. Specifically, highways authorities become 'carbon competent' without reliance on expensive external consultancies and specialist agency staff.

Pragmatic carbon reporting & analysis processes

With the support of the FHRG membership and, most notably and appreciatively, the seven authorities forming the CCAS Pioneer Group, the FHRG undertook the process of designing, testing, and refining the proposed carbon accounting processes. The final guidance describes two processes: a top-down carbon accounting process for annual carbon reporting, and a bottom-up carbon analysis process to drive carbon awareness and reduction initiatives.

The top-down, inventory-based approach to carbon accounting records emissions in four inventories for the reporting year:

  1. An inventory of owned or controlled premises or sites used to deliver the service.
  2. An inventory of owned, hired, leased or contractor-provided vehicles and plant.
  3. A schedule of directly employed or contracted / subcontracted staff.
  4. An inventory of all purchased products and services (including materials, third-party services, transport, and waste services).

Each inventory requires a detailed schedule of emissions sources and measured emissions. Carbon data is obtained from corporate functions, supply chain partners, staff records, vehicle fuel and maintenance records, and purchase orders and invoices.

Aggregating the total carbon emissions for these four inventories for the reporting year will provide the service-level carbon footprint. The inventory-based approach provides a straightforward, comprehensive method for carbon reporting, but lacks granular analysis necessary for identifying carbon hotspots at an activity level.

Bottom-up, activity-based carbon analysis evaluates the carbon emissions resulting from specific highways activities. Activities are classified as either repeating (for reactive, cyclical, and minor works) or one-off (for major schemes and capital works). In each case, resources are assigned to a unit of work (e.g., a m2 of resurfacing or a gang shift of pothole repairs) or project. This allocation provides a carbon profile for each activity.

Combined, these methods provide efficient, low-overhead processes for annual carbon reporting, whilst also providing the granularity required for carbon management and reduction.

Carbon analyser

Originally developed as a research instrument, Carbon Analyser was used to test the premises, accuracy, and completeness of the CCAS guidance. Beyond the research programme, Carbon Analyser has evolved into a whole-service carbon assessment toolkit, with each CCAS step fully supported in the software.

Also included within Carbon Analyser is the National Infrastructure Carbon Schedule (NICS); an online, up-to-date database of carbon emissions factors relevant to the sector. These factors include, inter alia, the new National Highways Carbon Library, the Department for Energy Security and Net Zero (DESNZ) Greenhouse Gas Conversion Factors (previously the BEIS conversion factors), the Inventory of Carbon and Energy (ICE) database, and many sector-specific emissions factors – all in one place and highlighting recommended factors where factors are duplicated.

Acknowledging the lack of accurate and consistent emissions data within the sector, Carbon Analyser supports interim accelerators - shortcuts based on national averages. This enables rapid carbon reporting in the first year, whilst flagging areas where data quality improvements should be sought in subsequent years.

The Carbon Analyser application is free-to-use for FHRG and ADEPT members, however, Microsoft Azure®, SQL Server®, Office 365 and hosting costs apply.

Benchmarking carbon & value for money

From its inception, a principal design goal of the programme was benchmarking. This functionality is provided by Carbon Analyser and the Microsoft Azure®, cloud-based, carbon dataverse. Each carbon assessment undertaken using Carbon Analyser contributes to the growing dataverse. This data can be used to benchmark the carbon profiles of services, functions, processes, materials, and policies.

Carbon Analyser also now includes the core functions and datasets of Value Analyser, the Value for Money (VfM) benchmarking tools developed by the FHRG in 2014. Together, these frameworks are already revealing the significant correlation between lower emissions and services with the highest VfM scores.

Moving forward, benchmarking will be instrumental in identifying opportunities for emissions reductions, whilst also ensuring services remain economic, efficient, and effective.

Conclusion - carbon reduction 

Carbon measurement provides the essential foundation for carbon reductions. The ability to identify and prioritise carbon hotspots will enable authorities to develop alternative, low-carbon or zero-carbon policies and methods, utilising recycled or low-carbon materials from qualified partners dedicated to a zero-carbon future.

As part of its work with ADEPT, the FHRG is supporting many of the Live Labs 2 programmes with a range of tailored support packages. Find out more here.


Simon Wilson, Director at Proving Services and Research Director at FHRG

Further information

  • Carbon Calculation
& Accounting Standard (CCAS) - Carbon Reporting Guidance for Local Highways Authorities 
    (GHG Scopes 1, 2 & 3) is available here.
  • More information on the Future Highways Research Group is available here.
  • More information on Proving Services is available here.
  • More information on the FHRG's work with Live Labs 2 is available here.

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