Urban infrastructure development is one principal way people are transforming the natural world and their living conditions. It is important for humanity, but it can also cause major impacts to the environment, such as huge amounts of solid waste and CO2 emissions. Considering this, the circular economy (CE) is a promising alternative to the traditional “make, use, and dispose” linear economy model. However, as a strategy for sustainable development (SD), the CE is still in its infancy in the urban transport infrastructure sector. Therefore, this article aims to guide the implementation of CE during transport infrastructure projects. To achieve this goal, a literature review and case study were adopted as the research methods. After reviewing existing well-established CE frameworks, the iReSOLVE (implement, Regenerate, Share, Optimize, Loop, Virtualize, Exchange) framework is recognized as the most comprehensive one. Upon it, an analytical framework containing specific-related aspects of CE in urban transport infrastructure projects (which belongs to meso-scale) is proposed (coined as the 4Wh-iReSOLVE framework). The 4Wh means Who, When, Where, and What. The proposed framework offers insight into potential CE activities for transport infrastructure projects and assists in assessing the performance and impacts of CE of these projects to cover the gap of the neglected meso-scale. Ten circular viaduct project initiatives in the Netherlands are used as case analyses with the 4Wh-iReSOLVE framework. The results present the highlights of the circular viaduct initiatives in the Netherlands, with CE activities categorized into five groups (design-related strategies, general CE strategies, implementation, management, and related digital technologies and materials, as well as environmental sustainability). As verified by several experts of the projects studied, it can be concluded that the 4Wh-iReSOLVE framework is suitable for transport infrastructure project CE analyses and implementations. It can potentially be a suggested guideline in future policy documents.@en

Chinese cities are experiencing rapid urban development while facing severe challenges of environmental pollution. China's central government has proposed several policies to reduce urban waste. However, little is known about the adoption of these policies. Here, we raise the question how can circular policies be classified, and how can this classification be applied to cities in China that wish become zero-waste cities? We develop a framework to classify urban waste policies according to: (a) the “5R” principles (“Rethink”, “Reduce”, “Reuse”, “Recycle”, and “Recover”), (b) four types of waste (industrial, agricultural, municipal, and hazardous) and (c) six types of policy instruments (legal, economic, network, communication, innovation and projects). We use this framework to analyze urban waste policies implemented by sixteen zero-waste demonstration projects in China. The present study emphasizes combinations of policy instruments, “R” strategy and waste type in the implementation of zero-waste policies. We find that the “Rethink”, “Reduce”, and “Recycle” principles have been widely implemented by local authorities in contrast to the principles “Reuse” and “Recover”. Local governments address waste management by embracing regulations, innovation instruments, and project arrangements, while network-based, economic, or communicative policy instruments are used less often. Based on the results we suggest that local governments embrace a comprehensive approach to the use of the “5R” principles and deploy a diverse portfolio of policy instruments.@en

In response to the mounting environmental problems the circular economy (CE) has become a popular policy concept to achieve sustainable production and consumption goals (SDG12). In line with this China's national government has issued and implemented a series of policies over the last fifteen years, leading to a sudden increase in the volume of CE policies. In the literature this phenomenon is referred to as ‘policy accumulation’, a concept which occurs when governments adopt increasingly more policy than they terminate. In the case of China, the question can be raised how CE policy accumulation has manifested. The present paper analyses policy on national policy spanning 2006–2021 and uses expert interviews to gain more insights in factors driving policy accumulation. Results show that after a stable period with limited growth (2006–2015) government issued increasing numbers of policy over 2016–2021. CE policy goals experienced a shift in focus from improving production efficiency via lowering of consumption patterns, to embracing whole life cycle thinking. CE policy instruments moved from predominantly economic instruments (2006–2015) to regulatory instruments along with accompanying communicative and network instruments (2016–2021), which indicates a move from a market and innovation policy approach to a more centralized model emphasizing hierarchical instruments. Several factors explain for CE policy accumulation: (i) a response to economic growth and environmental degradation; (ii) national government institutions, their interests and agendas; and (iii) policy learning. Implications pertain to future research critically analyzing CE policy accumulation in other contexts or in sub-domains regarding topics referring to SDG12.@en