Across both developed and emerging economies, road transport remains the backbone of mobility systems and carries the overwhelming majority of people and goods. Yet this dominance also means that roads are the single largest source of transport-related greenhouse gas emissions — a dual reality that now defines the challenge of sustainable road development.
Road Transport: The Cornerstone of Economic Activity
The IRF World Road Statistics (WRS) 2025 Edition reveals that road networks remain the predominant mode for both passenger and freight movement in Europe and North America, underscoring their indispensable role in regional and global economies.
Achieving the European Union’s climate neutrality objective by mid-century will depend critically on the pace and depth of emissions reductions in the transport sector. While energy, industry and power generation have made measurable progress in decarbonisation, transport remains one of the most challenging sectors to transition. Within this context, road transport stands out as the single largest contributor to transport-related greenhouse gas emissions, making it a decisive lever for Europe’s net-zero ambition.
Transport currently accounts for around 25% of total EU carbon dioxide emissions, with road transport responsible for approximately three-quarters of that share (EEA, 2024). Unlike other sectors, where emissions have shown sustained downward trends, road transport emissions have proven more resistant to long-term structural decline, reflecting continued growth in vehicle ownership, freight demand and road traffic. Understanding how emissions have evolved in recent years, and whether observed reductions reflect lasting structural change or temporary disruption, is therefore essential for assessing Europe’s progress toward a net-zero transport system.
In Europe (Figure 1), road freight accounts for 81.9% of total tonne-kilometres, compared with 14.2% for rail and 3.8% for inland waterways. For passenger travel, 88% of all passenger-kilometres occur on roads, while rail represents only 12%.
In North America (Figure 1), the pattern is similar. Roads carry about 50.1% of total freight, with rail contributing 38.4% and waterways 11.5%. In passenger mobility, road transport’s dominance is nearly absolute, representing 99.5% of all passenger-kilometres.
These figures underscore that, despite progress in alternative modes, economic growth and logistics efficiency continue to hinge on extensive road use. Roads remain indispensable for accessibility, trade, and service delivery, yet their sheer volume of activity creates parallel pressures on congestion, safety, and environmental performance.
The Climate Cost of Road Dependence
The environmental implications of this modal imbalance are clear. According to EEA (2024), transport contributes roughly 25% of total CO₂ emissions in the European Union, with road transport responsible for 75% of that share (Figure 2).
WRS data show that road transport emissions in Europe exceeded 800 million tonnes in 2018 and 2019 before falling to around 700 million tonnes in 2020 due to COVID-19 restrictions. While a modest rebound occurred in 2021–2022, emissions began declining again in 2023, suggesting some emerging structural shifts. However, much of the short-term reduction remains linked to temporary behavioural and economic effects rather than systemic transformation. North American transport emissions data (SLOCAT, 2023) show a decline by 7% between 2019 and 2021, with a further 0.9% reduction in 2022. Recent data (SLOCAT, 2025) suggest an increase in transport emissions for 2023 (0.7%), reaching 1,9 million tonnes of CO2. The pandemic contributed to an estimated 200 million tonnes of CO2 reduction, as emissions in 2021 totalled 1,813 million tonnes, below the projected 2 gigatonnes.
Decoupling Mobility from Emissions
While rising vehicle ownership and road traffic typically lead to higher emissions, various factors can mitigate this relationship, such as environmental regulations, the average age of the vehicle fleet and the proportion of hybrid or electric vehicles in use. Across Europe, a clear positive relationship exists between road activity and CO₂ output, yet several countries demonstrate that policy and technology can alter this trajectory. For instance, Germany, despite its extensive vehicle fleet and dense traffic network, records lower emissions than would be expected based on volume alone. Rather than constituting an outlier, this outcome likely reflects the effects of stricter environmental standards and faster fleet renewal rates in the country, which have led to a higher prevalence of low-emission vehicles and technologies.
Similar dynamics are emerging across several European countries (Germany, Italy, Sweden)1, where accelerated electrification of the vehicle fleet, stricter emissions standards (such as Euro 6 – with successive tighter updates – and the upcoming Euro 7 proposal) and investments in alternative fuels are beginning to decouple mobility demand from rising CO₂ emissions. This shift highlights the need for an integrated approach: aligning technology deployment, regulatory action and behavioural incentives to advance the EU’s long-term decarbonisation goals for transport. To ensure these trends translate into lasting change, emissions must continue to be closely monitored, supported by more detailed data on vehicle type, energy source and usage patterns. Such evidence is essential for assessing progress and guiding future policy toward a truly zero-carbon transport system.
Across the Atlantic, similar efforts to decouple mobility demand from emissions have gained momentum, though with greater policy volatility. In the United States, large-scale federal interventions have catalysed unprecedented investment in cleaner transport technologies. The Inflation Reduction Act (IRA) of 2022 marked the most significant climate and energy legislation in U.S. history, allocating extensive funding to support the transition toward zero-emission mobility. Within the transport sector, the IRA’s consumer and manufacturer tax incentives spurred an estimated USD 125 billion in new commitments to domestic electric vehicle and battery production — a major step toward greening the road sector.
However, progress has been tempered by recent policy reversals and fiscal constraints. Early 2025 saw the suspension of key disbursements under both the IRA and the Bipartisan Infrastructure Law, effectively halting federal mandates and subsidies for electric vehicles. This shift has reintroduced uncertainty over long-term climate policy and the stability of private investment. As in Europe, the success of decarbonisation in North America hinges not only on technological progress but also on sustained regulatory clarity and financial commitment.
Broader economic pressures are also reshaping the policy landscape across regions. Rising public debt, competing budget priorities and fluctuating political agendas have constrained public expenditure on sustainable infrastructure. The question now is whether the significant gains achieved in electric vehicle (EV) adoption and clean mobility infrastructure can be preserved without consistent policy support. Continued collaboration across federal, state and industry actors will be crucial to ensure that recent momentum in low-carbon transport does not falter amid fiscal tightening and shifting political winds.
The new IRF World Road Statistics (WRS) 2025 edition features updated data for over 200 countries and territories and more than 200 indicators covering key topics such as road networks, traffic volumes, multimodal transport comparisons, vehicles in use, road accidents, expenditures and revenues and many others.
The IRF Data Warehouse offers free, intuitive, interactive tools that allow users to perform in-depth analyses, compare multiple metrics and generate customised time-series charts.
For more detailed information on key statistical indicators in the road and transport sector – whether for a specific country or a global overview, please visit the IRF World Road Statistics website or email us at stats@irfofficial.org.
This article is part of the WRS Road Data Snapshot Series developed by IRF, with support of TotalEnergies Foundation and Michelin Corporate Foundation.
References
1Chovancová, J., Popovičová, M., & Huttmanová, E. (2023). Decoupling transport-related greenhouse gas emissions and economic growth in the European Union countries. Journal of Sustainable Development of Energy, Water and Environment Systems, 11(1), 1-18.
Shares of GHG emitted by different transport modes (%) in EU-27 total GHG emissions. European Environmental Agency. 2024. URL: https://www.eea.europa.eu/en/analysis/publications/ sustainability-of-europes-mobility-systems/climate/shares-of-ghg-emitted-by-different-transport-modes-in-eu-27-total-ghg-emissions
SLOCAT. (2023). Transport, climate and sustainability global status report: 3rd edition. https://gsr4.slocat.net
SLOCAT. (2025). Transport, climate and sustainability global status report: 4th edition. https://gsr4.slocat.net
