Embodied Emissions in Rail Infrastructure: A Critical Study

Abstract

This study investigates the state of knowledge in quantifying the embodied greenhouse gas (GHG) emissions in rail infrastructure and develops a novel underspecified model to evaluate the effect of external design factors on the embodied construction materials of an excavated rail station infrastructure. Starting with a critical literature review that identified 22-publications, containing 57 rail infrastructure case studies, the study examines the GHG impact per kilometre of infrastructure reported across the case studies and compares the boundaries, functional units, methods, and data used. This study presents the need for standardization in embodied emissions reporting and shows that different external factors (which are water table, soil type, floor height, number of train cars, station length and building codes) uniquely influence the embodied rail infrastructure construction materials. The study provides a flexible planning level method for engineers, urban planners, and policy makers to preliminarily analyze embodied emissions associated with rail station infrastructure.