London Boroughs Low Carbon Transport Study


City Science was commissioned to undertake a Low Carbon Transport Study for Westminster City Council (WCC) and Royal Borough of Kingston (RBK), who sought to understand the borough level actions required to meet their transport net zero goals. We constructed an evidence base through literature review, data-analysis and stakeholder engagement, which was presented to the clients in a a series of workshops, written reports, and online access to our Transport Decarbonisation Tool.

“Westminster City Council and Royal Borough of Kingston were very pleased to work with City Science on this project. We were looking for a robust, data led project that was a first for us, and we got just that from City Science who are clearly experts in the field. They worked to programme and budget and were flexible and responsive throughout the project and we are very pleased with the outcome.”
Damian Hemmings, Climate Emergency Programme Director (WCC) & Matt Hill, Assistant Director - Highways, Transport, and Regulatory Services (RBK)


London Councils and London Environment Directors Network have collaborated to develop seven climate programmes for London. WCC and RBK are leading on the Low Carbon Transport Programme which recognizes the need for additional borough-level data relating to transport decarbonisation. Many London boroughs have set net zero goals, but there is little information readily available to indicate an effective strategy for them to meet these goals. Most of the information available relates to the London-wide level. However, to inform local policies the boroughs require an evidence base which takes into account their local situation. Our commission was to address this and create locally specific evidence bases for WCC and RBK, allowing them to start to develop a pathway to net zero. We therefore developed innovative methods for combining existing data and give the borough-level resolution required.

City Science Response

From our industry-leading experience in supporting clients with transport decarbonisation, we have established a framework to structure projects of this type. This tried-and-tested framework is effective, naturally aligns with DfT’s forthcoming Quantified Carbon Reduction guidance (not formally adopted yet), and is flexible enough to respond to client’s individual needs. Our response followed the key steps of that framework.

  1. Understand Current Emissions - We used innovative techniques to produce low-cost models of transport carbon in the boroughs, split by key categories such as vehicle type, trip length and journey purpose. These were then analysed to identify the key sources of emissions in the boroughs, hence informing challenges and opportunities for the boroughs.
  2. Forecast Emissions Under Different Scenarios & Identify Emissions Gap - We undertook further modelling to forecast the emissions pathways of the boroughs under various scenarios – two of which are illustrated below for one of the boroughs, with the difference between the emissions pathways representing the Local Emissions Gap which must be addressed by local interventions.
    • National & Regional Policy represents the borough emissions in the case that only national and regional (e.g. the London Mayor’s Transport Strategy) policy is enacted, and the borough takes no local action.
    • Local Target represents an indicative emissions pathway for the borough to achieve its target net zero year of 2038.
  1. Shortlist Local Low Carbon Interventions - Drawing on our Low Carbon Intervention database (compiled through experience of delivering transport decarbonisation projects to a range of clients, and production of the RTPI’s Net Zero Transport report), we developed a long list of options which were suited to the boroughs. These were categorized using the Avoid-Shift-Improve framework, and a series of themes including infrastructure, policy and legal, behavior change and economic. Through stakeholder engagement and a high-level appraisal these were then refined into a short list.
  2. Quantify Carbon Reduction Owing To Interventions - The short list of interventions identified in the previous stage were then assessed individually to quantify their impact on transport, for each borough specifically. This allowed a greater understanding about the relative contribution of different interventions in reaching net zero, and hence prioritization.
  3. Communicating Findings - As well as through end of project reports, we reported the findings to the clients and wider stakeholders in a series of presentations – allowing discussion about the wider conclusions. Similarly, City Science also added the boroughs to their online decarbonisation tool (screen shot below). This free-to-use tool allows users to interactively investigate the impact of different interventions. This innovative approach increases transparency, engagement and understanding.


Our project revealed that decisive, collaborative action is required at the local, regional and national level if the boroughs are to meet their net zero targets. The relative contribution of different interventions was, in some cases, surprising and highlighted the necessity of taking a ‘do everything’ approach. The strength of this finding led to WCC and RBK commissioning an extension to the project so that additional inventions could be quantitively assessed. Based on the project’s success, we have been engaged by other London borough councils to deliver similar studies.