Applying circular economy principles in rail infrastructure projects

The circular economy represents a shift away from society’s traditional linear take-make-use-and-dispose model of consumption, which exacerbates resource scarcity and climate change. It could also enable built environment subsectors like rail infrastructure to operate and provide value for society more sustainably. However, while strategies exist that could support the circular economy transition, as yet there is little evidence of their application in rail infrastructure projects. Despite growing research into circular economy in the built environment sector, most studies address buildings rather than infrastructure, heedless of sectoral differences, and rely on secondary data. There is a need for more tailored research based on primary data to provide new insights and guide the rail industry towards circular economy implementation.

This research investigated the importance of circular economy implementation strategies, barriers and enablers for UK rail infrastructure projects through an industry-wide survey, from which a framework was developed using ‘theory of change’ to provide more tailored guidance. A mixed approach was adopted, wherein various data collection methods were used to supplement quantitative data with qualitative information and more fully address the objectives. The industry-wide survey included an online questionnaire (n=50) and 15 semi-structured interviews with representatives of UK rail infrastructure organisations. It revealed that resistance to change was seen as being even greater than for buildings, which could hinder circular economy implementation. Client leadership was identified as key in this respect, along with support from government and the supply chain.

The highest-rated strategies, barriers and enablers from this survey informed development of a framework to apply circular economy principles in rail infrastructure projects, which interviewees were also questioned about. Their recommendations were reviewed against relevant literature in order to identify a preferred development approach, this being theory of change. This approach breaks a project or programme down into the intermediate steps required to realise an overall long-term aim through various strategies. A framework was developed, comprising three strategies that were rated highest at project brief and design, these being identified as the most important stages for circular economy implementation. The framework was also divided into two levels to allow for a modular approach whereby additional strategies can be included as required.

A semi-structured focus group was held with six representatives of UK rail infrastructure client, consultant and contractor organisations in order to review the framework. This was informed by a short questionnaire survey, which asked participants to rate the framework in terms of its overall structure, relationship between levels, content and flow. The group discussion focused on how these elements could be improved, with participants also being asked which stakeholder is best placed in terms of implementation and management. This resulted in several improvements, the main change being to include a feedback loop with piloting before wider implementation. Also, more interventions/activities were placed on consultants and contractors in recognition of their responsibility for proposing innovative solutions.

The main contribution of this study is to provide knowledge and guidance on an important but under-researched topic. In so doing, it provides industry and the research community with a more tailored understanding of those factors that most influence circular economy implementation for rail infrastructure projects. By developing a framework based on this understanding, it also provides stakeholders with specific guidance on driving the circular economy transition. Furthermore, employing theory of change to provide this guidance is itself a novel use, which has the potential for wider application. Likewise, while this study focuses on UK rail infrastructure, certain findings will be more widely applicable, which presents an opportunity for other research to address by investigating similarities between different countries and sectors.