Long-term spatial and temporal projections of road transport emissions: The case study of Budapest

The transportation sector is crucial for modern economies but also a significant source of greenhouse gas (GHG) emissions and air pollutants, especially in urban areas. This study explores the environmental impact of road transport in Budapest, forecasting warm-vehicle emissions for 2020, 2030, and 2050. We analyze future emissions across vehicle technologies and fuel types using advanced emission modeling tools, including HBEFA and COPERT, within the PTV VISUM software framework. Our research (i) assesses how future changes in vehicle technology, emission standards, and traffic demand influence GHG and air pollutant emissions, (ii) analyzes the spatiotemporal patterns of emissions in urban versus rural zones, (iii) evaluates the extent to which projected emissions align with EU climate targets for 2030 and 2050. The analysis excludes heavy-duty trucks and includes only hot exhaust emissions, without cold-start or evaporative components. Results indicate significant reductions in emissions. By 2050, CO 2 -equivalent emissions will decline from 7 million tons annually in 2020 to 4.24 million tons, primarily due to fleet electrification and improved vehicle efficiency. Exhaust pollutants such as NOₓ, CO, and PM 2.5 are expected to decrease by over 90%, enhancing urban air quality. However, non-exhaust emissions from tire and brake wear show minimal reductions, necessitating further policy measures. Spatial analysis shows that urban areas currently have higher emissions than rural zones. By 2050, targeted interventions, including electrification and infrastructure improvements, are expected to reduce these disparities. This research supports evidence-based transportation policies aligned with EU climate goals and provides an analysis framework adaptable to similar urban areas for sustainable transport.