Identification of the potential for carbon dioxide emissions reduction from highway maintenance projects using life cycle assessment: A case in China

Abstract

This paper investigates the neglected potential of carbon dioxide (CO2) emissions reduction from highway maintenance projects. Conventional assessment (CA) on fuel combustion of off-road equipment during maintenance, and a comprehensive life cycle assessment (LCA) on the materials production, fuel production, traffic delay and maintenance equipment were conducted for four typical maintenance schemes in a real highway project in China, through Microsoft spreadsheet models, VISSIM and CMEM model. The focus of the case study was to understand the magnitude and source of the gap of CO2 emissions assessment results between LCA and CA. In this study, we also checked scenarios that apply a few mitigation options from several industrial sectors in four typical maintenance schemes to investigate how significant potential for decarbonization of the highway maintenance might be neglected without using LCA. Results suggest that there exists an obvious gap between the total CO2 emissions per lane per kilometer of CA and that of LCA, and the gap is even up to 22 times of the CA results in this specific case study. Traffic delay caused by the lane closure has the largest contribution to the gap, while the shares of materials production and fuel production match. The scenarios analysis of mitigation strategies associated with the transport sector and other industrial sectors indicates that the LCA model could effectively identify the dominant inputs and CO2 emissions outputs of individual maintenance process in the complicated transport system, while CA may neglect or underestimate the potential for adopting some mitigation strategies, especially for mitigation options from other industrial sectors.