The central contribution of the book is making new space for time and temporality in the global ‘infrastructure turn’. Contemporary infrastructure scholarship is highlighting the significance of infrastructural systems to the production and reconstruction of urban and regional space, yet we and our contributors argue it is the combination of temporalities and infrastructures that infuses cities and regions with rhythm and meaning. The book's chapters demonstrate the complex and multifaceted ways that time pervades the city through infrastructure and shapes the infrastructures of cities themselves. We have encountered the evolving materiality of water pipes and pumps, of concrete and rails, of electrical microgrids and global pathogens, and the resultant speeds and time frames through which financial value unevenly flows across time and space. The chapters’ empirical investigations have revealed a wealth of formal and informal social infrastructures that enable, produce, and replicate socio-technical configurations, from unfurling forms of financialization and state de-risking to the regulatory regimes shaping our ability to access urban space. We have also seen how time can be put to work (pasts mobilized, futures engaged, the present contested and claimed) to understand our current infrastructural worlds and foster their potential alternatives. What we hope emerges from these temporal adventures in infrastructure is a renewed appreciation of ‘infrastructure time’ as a social construct whose plurality – that is, the co-presence of multiple temporalities – informs, and is informed by, diverse, overlapping, and sometimes paradoxical human experiences (Nowotny, 1994).

The challenge for future infrastructure studies is to create geographically contextual accounts of these pluralistic temporal modalities, considering empirical detail about both the microseconds involved in self-healing systems and the epochal transformations of the Anthropocene. As we have seen from the streets of San Francisco to the fields of Laos, infrastructural times are embodied as people navigate their temporal and spatial worlds and are tempered by their individual agency and social constraints. Studying infrastructure's temporalities thus hinges on incorporating multiple knowledge systems (academic and lived) and requires us to recognize multiple ways of knowing and doing infrastructure time.