The “Polluter Pays” Principle in Transportation: The Impact of Environmental Taxes on CO2 Emissions in V4 Countries

Background: Transport remains one of the hardest sectors to decarbonize in the European Union, and the effectiveness of environmental taxation as a “polluter pays” instrument remains contested for the institutionally distinct Visegrad Four (V4) countries. Methods: Using a balanced panel of four V4 countries over 2000–2024 (n = 100 observations) from Eurostat, we estimate fixed-effects models with Driscoll–Kraay standard errors, complemented by two-way fixed effects, lag, interaction, and robustness specifications, including a sensitivity test for mechanical endogeneity. Results: GDP per capita and freight transport volume are positively associated with emissions (elasticities 0.244 and 0.230, both p < 0.001), while renewable energy share is negatively associated (−2.93%, p < 0.001). Environmental taxes show no significant association at any lag, and their positive association is strongest where highway infrastructure is least developed, disappearing where it is most developed. Freight transport remains the only robust driver once year effects are controlled for; a tax-to-freight intensity indicator reveals a significant three-year lag effect. Conclusions: Environmental taxation alone is not robustly associated with lower transport emissions in the V4; its association is conditional on infrastructure development and best complemented by renewable-energy investment. Findings should be read as descriptive associations rather than causal effects.