The urban built environment concentrates due to the growing urbanization trend, triggering construction and renovation works in urban areas. Although construction works often revitalize cities upon completion, the associated logistics activities engender a significant financial and environmental footprint if not handled appropriately. Cities have the largest potential to reduce negative impacts through requirements on construction logistics. However, today, there is a lack of knowledge within cities on how to set such demands and how to involve and manage the numerous and varying stakeholders in these processes. This paper presents a participatory decision-making framework for the governance of urban construction logistics on economic, environmental and societal levels, building further on the Multi-Actor Multi-Criteria Analysis (MAMCA). The framework was then implemented on a use case in the dense urban Brussels-Capital Region (Belgium), gathering a wide variety of stakeholders in the context of a sustainable Construction Logistics Scenario (CLS) evaluation. Special attention was paid on the identification of implementation barriers and the role of governments to facilitate the introduction and city-wide roll-out of novel CLS. Findings show how different processes are site-, actor- and condition-specific, thereby delivering a common built object which is often based on different motivations and concerns. The study proposes a flexible, replicable and upscalable framework both from an inter- and intracity perspective, which can serve to support (1) the management of processes and CLS, (2) the management of people and the community, and (3) the project and city, in the context of multi-level governance.

Urban areas pay increasing attention to new construction and infrastructure works, mainly due to the rapid global rise in urbanisation. In the long run, these works have a positive correlation with the economic and social attractiveness of cities. Construction strongly relies on logistics activities, which cannot be neglected in the environmental equation. An important aspect in tackling the negative effects of construction logistics (CL) lies in understanding the source and mitigation potential of the impacts incurred. However, currently, limited robust impact assessments are available for this sector. Given the lack of these rigorous assessments, it is difficult to evaluate the environmental criteria concerned, especially when comparing innovative CL solutions. In this paper, we present a holistic sustainability assessment framework designed for CL activities based on life cycle approaches, which covers four main iterative steps: (1) goal and scope definition, (2) data identification and availability, (3) scenario and setup evaluation and (4) environmental impact assessment. To measure both the off-site and on-site CL impact, two distinct and complementary methodologies are used: External Cost Calculations and Life Cycle Assessment. The framework was implemented on a pilot case in the Brussels-Capital Region (Belgium). It provides a holistic view of CL impacts for policy evaluations and implementations on the project, portfolio or city level. The results show that off-site zero-emission construction vehicles are the way forward if cities want to achieve environmental goals by 2035. However, market readiness for high-capacity vehicles must be considered. Otherwise, the positive effects on air pollution, climate change and noise are offset by a saturation of the road transport network and its associated congestion and infrastructure damage costs.

Introduction. The ongoing urbanization trend makes local governments densify their built environment, hence stimulating construction and renovation works in urban areas. Construction intrinsically strongly relies on logistics activities, which in turn are the source of environmental nuisances. The latter are referred to as external costs when they are not borne by the polluter himself, such as greenhouse gas emissions, air pollution, congestion, etc. Accurate external cost calculations require accurate data to consider significant calculation-variables. However, current calculations are often based on the number of vehicles used and on transported volume rather than vehicle- or tonne-kilometres, hence not adequate to conduct external cost calculations. Methods. The MIMIC-project¹ aims to reduce the impact of construction logistics. Therefore, an integrated impact assessment framework will be developed, assessing the economic and environmental influence of different off-site construction logistics solutions. The necessary data to conduct such an impact assessment are however not always available, complicating calculations. This paper highlights the current gap in accurate data on urban construction logistics flows, the considerable uncertainty about existing figures on construction transport and their methodology, and presents the data availability issue in the development of such a framework, using empirical research. Results. Logistics flows data are typically scattered amongst different actors and various in format. Harmonizing different data categories and sources to feed the framework with relevant logistics variables, this paper presents what is possible to calculate using available data in 4 pilot cases in Belgium, Sweden, Norway and Austria. The various data sources highlight the complexity to develop a framework flexible enough to cope with specific local constraints, whilst generic enough to allow comparability across the European cases, and ultimately across construction logistics globally. Furthermore, a shift is needed towards other data collection methods (GPS, digital waybills etc.). Conclusions. This paper presents the data availability issue in the development of an impact assessment framework for construction logistics, harmonizing different data sources in order to conduct external cost calculations for construction transport.