Rethinking the carbon dioxide emissions of road sector: Integrating advanced vehicle technologies and construction supply chains mitigation options under decarbonization plans

Abstract

The single life cycle assessment on advanced vehicle technologies and clean construction supply chains offers the potential for reducing carbon dioxide emissions from vehicle operation and road infrastructure separately. However, the impact of the combination of these two aspects on CO2 emissions mitigation of road life cycle is less known even though it is critical to the longer-term road transportation decarbonization and long-range policy making for transportation sector, especially under latest worldwide net-zero carbon emission goal. In this study, taking a real project-level asphalt pavement freeway with 15-year life span in China as a case, the amount and hot spots of CO2 emissions of road transportation were evaluated by considering emissions abatement measures of advanced vehicle technologies and construction supply chains which are theoretically practicable in near-, mid-term and long-term future (from 2020 to 2035). Furthermore, a scenario-based sensitivity analysis on different increasing scope together with various increasing degree of abatement levels over time for these measures is provided. Results demonstrate that the timely implementation of combined decarbonation measures of advanced vehicle technologies and construction supply chains by 2035 could reduce 16.3% of total CO2 emissions from a road life cycle. In detail, for maintenance activities and use phase, total CO2 emissions reduce 32% and 16.2% separately. The construction equipment still is the top emissions contributor for maintenance activities. The hybrid electric vehicles (HEV), not battery electric vehicles (EV), replaces conventional internal combustion engine vehicles (ICEV) and becomes the largest source for passenger-related CO2 emissions from use phase by 2035. Findings are sensitive to assumptions regarding cleaner fuel-produced cement, construction equipment and asphalt, and the market penetration of new energy vehicle. The tight and accelerating pace of primary abatements assist in alleviating the infrastructure carbon lock-in effects caused by maintenance activities with 15% additional CO2 emissions saving, but not bring about a significant additional reduction (no more than 2.0%) for total road life cycle CO2 emissions. Current abatement measures are effective but obvious emissions mitigation substitutes of a road is still required, especially innovative road structure and cleaner supply chains inputs as well as deeper decarbonized electrified vehicle.