Transport Decarbonisation Tool for Local Authorities


With 466 parish, district, county, unitary and metropolitan councils now having declared a Climate Emergency, there is now a huge desire at a local level for decisive climate action. As the biggest contributor to carbon emissions in the UK transport represents a critical challenge in achieving decarbonisation. A key challenge that local authorities face is that monitoring and accounting for carbon within the development of transport policy is complex and involves consideration of a wide range of factors including regional growth, fleet vehicle mix, residents’ travel behaviour and land use planning considerations. Moreover, there are no existing modelling tools which allow evaluation and monitoring of transport carbon impacts.



Developing policies that embed carbon accountability and track the success of these policies is an essential challenge to delivering the net zero objective. City Science was awarded funding by the Department for Transport (DfT) through a transport technology research innovation (T-TRIG) grant to develop a methodology and evidence-based web based tool to support local authorities such as Somerset County Council in the development of their decarbonisation roadmaps.

The scope of the tool aimed to:

  • Reconcile national carbon accounting to a local authority level, with an ability to integrate locally specific datasets.
  • Enable local authorities to test aspirational transport policies.
  • Allow local authorities to track policy impacts on an annual basis.
  • Link detailed transport models (describing travel patterns), fleet statistics, electric vehicle strategies and national and local policies.

City Science Response

Our team of software developers built the online 'Decarbonisation Tool' in partnership with Somerset County Council to take complex transport data and convert this into carbon strategies in a highly flexible and user-friendly way. The tool has been designed to be used at both the initial roadmap development stage to inform policy prioritisation as well as at annual monitoring intervals thereafter.

We developed the technical capability of the tool to be highly flexible, allowing local authorities to input key elements such as their carbon emissions reduction target, the zero-carbon policy year alongside the anticipated impacts of policies and measures covering aspects such as electrification, public transport, active travel, new developments and freight modelling. The tool is underpinned by national and locally specific open datasets to provide a robust and annually replicable evidence base. The outputs allow local authorities to ascertain gaps between their existing plans and zero carbon ambitions.

From inception to delivery, innovation was at the heart of our approach. One particularly innovative element was the application of an accessible pathway visualisation output with the aim of unlocking public and stakeholder engagement through enhancing their understanding of the trade-offs and complexity of the decarbonisation process.

Our tool also differentiated from traditional transport models through providing a holistic focus of opportunities for decarbonisation and a clear indication of the trade-offs by embedding a 'What-if' functionality. While the T-TRIG grant has been used to prototype the solution, it is also intended that future development of the Decarbonisation Tool will be able to integrate with City Science’s award-winning Cadence platform to further enrich its capability.

Decarbonisation Tool Example 1
Decarbonisation Tool Output Example
Decarbonisation Tool Example 2
Decarbonisation Tool Output Example


Our successful delivery of the project was evidenced through positive feedback received during the testing phase from our end-user organisation Somerset County Council. The tool is now being extended to users across the UK.

To view a preliminary version of our Decarbonisation Tool please click here

To read a blog which discusses the use of the Decarbonisation Tool in more detail please click here