The CE4CE project has developed the CE4CE Knowledge Platform, a groundbreaking digital hub designed to foster the adoption of circular economy principles in public transportation systems. As a key output of the project, the platform supports stakeholders in identifying circularity gaps and life-cycle actors, enabling effective knowledge transfer, and showcasing selected lifecycle value chains. A major enhancement to the platform is the matchmaking forum — an interactive feature that connects public transport operators, suppliers, policymakers, and researchers. This forum facilitates targeted collaboration and business opportunities in the field of electric public transport, promotes the exchange of best practices, and helps forge partnerships that accelerate the transition toward circular and sustainable mobility solutions. The platform can be accessed here: https://circularity4publictransport.eu/

The transnational strategy formulates a joint vision and objectives to influence hard (material, technology, infrastructure) and soft factors (management practices, human preferences, cultural practices) to optimise energy use by recapturing waste energy and increasing the share of locally produced renewable energy sources (RES) in public transport operations along new life cycle value chains.

The transnational strategy formulates a joint vision and objectives to influence hard (material, technology, infrastructure) and soft factors (management practices, human preferences, cultural practices) to add and recapture value and optimise delivery of public transport infrastructure based on new life cycle value chains.

The transnational strategy formulates a joint vision and objectives to influence hard (material, technology, infrastructure) and soft factors (management practices, human preferences, cultural practices) to add & recapture value and optimise delivery of vehicles/rolling stock in public transport operations.

A jointly developed action plan was created to adapt the transnational strategy for optimising the use of waste energy and renewable energy sources in public transport operations to the regional planning context of the Municipality of Maribor. The plan identifies prioritized clusters of measures and defines related requirements in terms of infrastructure, technology, competencies, information, and knowledge. It was developed in agreement with life-cycle actors and stakeholders and also considers opportunities for value creation, as well as implications related to financing, stakeholder and supply chain management, procurement, costs, timelines, risks, and dependencies.

A jointly developed action plan was created to adapt the transnational strategy for preserving the value of infrastructure in public transport operations to the regional planning context of LVB, the public transport company in Leipzig. The plan identifies prioritized clusters of measures and defines related requirements in terms of infrastructure, technology, competencies, information, and knowledge. It was developed in agreement with life-cycle actors and stakeholders and also considers opportunities for value creation, as well as implications related to financing, stakeholder and supply chain management, procurement, costs, timelines, risks, and dependencies.

A jointly developed action plan was created to adapt the transnational strategy for preserving the value of infrastructure in public transport operations to the regional context of PKA, the bus operator in Gdynia, and the University of Gdynia. The plan identifies prioritized clusters of measures and defines related requirements in terms of infrastructure, technology, competencies, information, and knowledge. It was developed in agreement with life-cycle actors and stakeholders and also considers opportunities for value creation, as well as implications related to financing, stakeholder and supply chain management, procurement, costs, timelines, risks, and dependencies.

A jointly developed action plan was created to adapt the transnational strategy for preserving the value of rolling stock and vehicles in public transport operations to the regional context of ATB, the public transport company in Bergamo. The plan identifies prioritized clusters of measures and defines related requirements in terms of infrastructure, technology, competencies, information, and knowledge. It was developed in agreement with life-cycle actors and stakeholders and also considers opportunities for value creation, as well as implications related to financing, stakeholder and supply chain management, procurement, costs, timelines, risks, and dependencies.

The Guidelines for developing circular strategies in the public transport sector document introduces the CE4CE approach to circularity, outlines the strategies developed for Energy, Infrastructure and Rolling Stock, and showcases how these were translated into concrete local Action Plans. Drawing on practical experiences from strategy and action plan development, the document highlights key success factors, stakeholder engagement approaches, and recommendations to support the wider adoption of circular economy principles in the public transport sector.

Linked to output O3.1 – Digital infrastructure and vehicle optimisation through predictive maintenance in Leipzig, prototype modules for predictive maintenance were developed for (1) infrastructure and (2) fleet applications. These process-related and technical solutions are applied to selected sections of infrastructure and rolling stock to enable later scaling across the entire network. Transferability to other organisations is ensured through the specification of standardised interfaces, data formats and parameters, as well as through the demonstration of operational dependencies and a methodology for developing damage catalogues and conducting impact analyses.

Linked to output O.3.3 – Simulation of an e-corridor and energy flows to support circular scenarios for electrification upscaling (bus lanes, electric supply and in-motion charging) in Gdynia, a tool was developed to assess the value and costs of actions aimed at increasing the lifetime of infrastructure and vehicles, as well as optimising energy use. The solution included: a) the design of energy management scenarios, based on inputs from related activities such as investment costs and assumptions on the lifecycle of fleets and infrastructure; b) the development of a cost-benefit analysis model integrating internal benefits (e.g. extended asset lifetime) and external benefits (e.g. environmental impacts). The tool is available publicly at: https://ce4ce.ug.edu.pl/

Linked to O.3.5 – Demonstrating the feasibility of reusing trolleybus switches in Szeged, an evaluation document was developed defining criteria for reuse and outlining the actions required by other trolleybus service providers to adopt the solution for heavily used switches at specific locations within their systems. The document supports knowledge transfer and future implementation across other operators, while dissemination of the results is planned via trolley:motion to enable further extension of the activity.

Linked to O.3.7 – Analysis of used battery applications for storing renewable energy to power a fast charger in Maribor, a business model based on reusable batteries was developed in collaboration with life-cycle actors along newly defined value chains. As part of the small-scale pilot, the University of Maribor and the Municipality of Maribor also addressed existing legal barriers and formulated recommendations for required changes to relevant standards.

Linked to O3.9, an online second-hand marketplace / matchmaking platform was developed to crowdsource information needed to adapt the door opening and closing control mechanism for trams, as well as other critical components. In this case, specific information is collected for a defined tram part, while the broader objective of the solution is to enable information sharing between public transport life-cycle actors in order to support the development of circular services and product designs. The matchmaking forum can be accessed here: https://circularity4publictransport.eu/matchmaking-forum/

This handbook documents and disseminates the key pilot actions and solutions developed within CE4CE, providing practical insights and guidance for stakeholders seeking to apply circular economy principles in public transport contexts.