Traditional decision-making in the management of existing structures within the built environment has often emphasized cost-effectiveness, frequently at the expense of broader societal and environmental considerations. This narrow focus has led to sub-optimal choices regarding the replacement, renovation, and maintenance of these structures. However, a shift driven by the Sustainable Development Goals (SDGs) has recently prompted more comprehensive evaluations that now include environmental impact.
Environmental analyses for infrastructure assets like bridges and viaducts have typically centered on the impacts of material production and construction phases. Yet, these evaluations often fail to account for the full life cycle sustainability of the structures, focusing solely on the individual asset without considering its role within the broader transportation network. This oversight is especially problematic when making decisions about interventions on existing assets within congested transport networks. The interconnectedness of assets means that decisions affecting one structure can have significant repercussions on traffic flow and mobility across the entire network. Therefore, to ensure sustainability-centered choices for interventions on existing infrastructure assets, a shift is required towards decision-making that considers network interdependencies, informed by the underlying topology and travel demand patterns.
This paper introduces a novel decision-making approach, illustrated through a case study of a bridge in the metropolitan region of Amsterdam. By redefining system boundaries to include environmental impacts from traffic disruptions caused by construction and intervention activities, and by quantifying societal costs in terms of additional costs for users, this approach promotes a more comprehensive decision-making process. The proposed framework ensures that decisions regarding replacement, renovation, and/or traffic restrictions are not only technically feasible but also aligned with broader sustainability goals, leading to better balanced and transparent outcomes. The study highlights that incorporating network-wide impact and societal costs is essential for advancing the sustainability of interventions on existing concrete bridges.