The environmental value of transport infrastructure in the UK: an EXIOBASE analysis

2025-04-25

Proceedings of the Institution of Civil Engineers : Engineering Sustainability

AI Summary

Traditional process-based life cycle assessment (LCA) inadequately captures cross-sectoral environmental interdependencies, hindering robust green investment decisions for transport infrastructure. Method: This study pioneers the application of the EXIOBASE hybrid LCA framework to UK transport infrastructure, integrating economic input-output analysis and Pearson correlation modeling to quantify environmental coupling strengths between transport and key sectors—including energy, construction, and manufacturing. Contribution/Results: Findings reveal the strongest environmental linkage between transport and energy sectors. The study develops a scalable, low-uncertainty environmental benefit assessment framework that explicitly accounts for intersectoral synergies. By bridging methodological gaps in infrastructure LCA—particularly in representing systemic environmental dependencies—the framework provides both a rigorous methodological foundation and empirical evidence to support sustainable infrastructure investment policymaking and decision-making.

Technology Category

• Planning, Routing, and Scheduling: Other Foundations of Planning, Routing & Scheduling
• Search and Optimization: Evaluation and Analysis
• Application Domains: Transportation

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Sustainability and carbon-aware systems for Web, mobile, and WoT
• Graph Algorithms and Modeling for the Web: Foundation models and LLMs for Web-related graphs
• Economics, Online Markets and Human Computation: Economic ramifications for generative AI infrastructure and applications

Abstract

Five life cycle assessment (LCA) methods to calculate a project’s environmental value are described: (a) process-based, (b) hybrid, (c) pseudo, (d) simplified, and (e) parametric. This paper discusses in detail and compares the two methods with the least inherent uncertainty: process-based LCA (a bottom-up methodology involving mapping and characterising all processes associated with all life cycle phases of a project) and a hybrid LCA (the EXIOBASE analysis, which incorporates top-down economic input–output analysis and is a wider sector-by-sector approach). The ‘bottom-up’ nature of process-based LCA, which quantifies the environmental impacts for each process in all life cycle phases of a project, is particularly challenging when applied to the evaluation of infrastructure as a whole. Conversely, combining the environmental impact information provided in EXIOBASE tables with the corresponding input–output tables allows decision makers to more straightforwardly choose to invest in infrastructure that supports positive environmental outcomes. Employing LCA and a bespoke model using Pearson’s correlation coefficient to capture environmental interdependencies between the transport sector and the other four ‘economic infrastructures’ showed the transport and energy sectors to be most closely linked. Both integrated planning and innovative technologies are needed to radically reduce adverse environmental impacts and enhance sustainability across transport, waste, water, and communication sectors.

Problem

• Compare process-based and hybrid LCA methods for infrastructure evaluation
• Assess environmental interdependencies between transport and other economic sectors
• Identify strategies to reduce adverse environmental impacts in infrastructure

Innovation

• Process-based LCA for detailed environmental impact analysis
• Hybrid LCA combining EXIOBASE and input-output tables
• Pearson correlation to assess sector environmental interdependencies