Port cities, as crucial nodes in global supply chains, face challenges from both intense traffic emissions and vulnerability to climate-related extremes due to pollution density. Effective and near-term mitigation strategies for greener road freight are imperative to reverse the increasing trend of emissions. This study utilizes a high-resolution emission inventory from 1.2 billion global positioning system trajectories of heavy-duty trucks in Shenzhen, a global port city, to evaluate the combined effects of road network development and fleet electrification on emissions from 2016 to 2035, providing a basis for policy interventions applicable to various urban contexts. Our findings reveal that an integrated strategy decreases road freight emissions, cutting peak carbon dioxide and nitrogen oxide emissions by 34% and 43%, respectively, compared to electrification-only scenarios. While fleet electrification supported by net-zero emission grids is necessary, it is insufficient without addressing congestion and enhancing connectivity through expanded road networks. Spatial projections also assist targeted policymaking by showing how emission distributions shift with regional road network expansion.

Freight transport underpins economic development yet imposes substantial environmental burdens through heavy-duty truck (HDT) emissions. This study addresses the critical challenge of balancing pollution reduction with social justice in China’s freight sector. Analysing 51 billion signals from over one million HDTs, we create a high-resolution emission inventory revealing stark regional disparities in pollution exposure—with economically disadvantaged and vulnerable populations disproportionately affected. We introduce the Pollution-Benefit Matching Index (PBMI), which quantifies the mismatch between environmental costs and economic benefits at county level, identifying regions bearing high pollution burdens without corresponding economic gains. To address these inequities, we propose three strategic interventions: electrification of major freight corridors, implementation of a polluter-pays nitrogen oxides (NOx) mitigation levy, and establishment of HDT-restricted zones near rural schools. This integrated approach not only reduces emissions but also improves their distributional equity, providing a transferable analytical framework that may inform efforts to advance environmental sustainability and social justice in freight transport systems in other countries.