Suggested Citation:
Filani, Iyanuoluwa, Ali A. Butt, John T. Harvey (2026)

Brief: Benchmarking Global Road Transportation Greenhouse Gas Emissions from 2021–2050 

. Institute of Transportation Studies, University of California, Davis, Brief UCD-ITS-RR-24-106

Abstract:

Greenhouse gas (GHG) emissions from transportation are rising globally, particularly in emerging economies, where growing wealth increases vehicle ownership, vehicle use, and expansion of road networks. Road infrastructure is vital to economic development, but its construction, maintenance, and rehabilitation contribute significantly to GHG emissions. While extensive research and policy efforts have focused on emissions from vehicle operation, emissions from road infrastructure have not been systematically benchmarked to support mitigation strategies. A holistic lifecycle approach that integrates emissions from road construction, maintenance, vehicle production, operation, and road surface roughness provides a more complete understanding of climate impact from road transportation. To address these knowledge gaps, researchers at the University of California, Davis developed a framework to estimate lifecycle GHG emissions from road networks around the globe. This framework estimates emissions from 2021 to 2050, incorporating regional differences in road network expansion, vehicle fleets, and travel activity. The study offers regional benchmarks and identifies evidence-based opportunities to reduce infrastructure-related emissions and support more sustainable transportation. This brief summarizes the findings from that research and provides implications for the field.