Truck emissions span climate pollution, local air pollutants, fuel use and the transition to zero-emission vehicles. The statistics below distinguish global and regional estimates, measured tests, certification data, sales, forecasts and technology demonstrations.
Key Truck Emission Statistics
The most broadly useful truck emission statistics include:
- In the 2017 IEA baseline, global road freight produced more than one-third of transport-related CO2 emissions.
- In the 2017 IEA baseline, global road freight accounted for 7% of total energy-related CO2 emissions.
- In 2024, global road-sector emissions exceeded 6 gigatonnes of CO2.
- In the United States, medium- and heavy-duty vehicles accounted for 23% of transportation-sector greenhouse-gas emissions in the program fact sheet accessed in 2024.
- In the United States, medium- and heavy-duty vehicles made up 10% of road vehicles in the same fact-sheet population.
- More than 3 million Class 6 and 7 vehicles were in use in the United States in the program fact sheet accessed in 2024.
- An estimated 72 million people in the United States lived near truck freight routes in EPA’s 2022 rule announcement.
- EPA’s 2045 projection estimated up to 2,900 premature deaths avoided annually under its heavy-duty rule scenario.
- EPA’s 2002 tests found an average 144 grams of NOx per hour from idling Class 8 diesel trucks.
- EPA’s 2002 tests found average diesel consumption of about 0.82 gallons per hour while idling.
- The EU and UK had 7,159,038 trucks in 2021.
- EU and UK tractor-trailers covered an average 530 kilometers per day in the 2024 operating statistic.
- EU-27 zero-emission heavy-truck sales reached 2,600 vehicles in 2023.
- Zero-emission heavy trucks represented 0.9% of new EU-27 heavy-truck sales in 2023.
- Germany accounted for 29% of EU-27 zero-emission heavy-truck sales in 2023.
- DOE SuperTruck 1 demonstrated a 50% increase in Class 8 freight efficiency during its 2009–2016 program.
- All SuperTruck 2 teams achieved more than 100% improvement in freight efficiency measured in ton-mpg during the 2016–2023 program.
- SuperTruck 3 set a 75% lifecycle reduction goal for medium- and heavy-truck greenhouse-gas and air-pollution emissions for its 2023–2027 program.
Contents
- Global truck emission scale and freight’s climate share
- U.S. truck emission data and health exposure
- Heavy-duty truck idling emissions
- EU truck emission intensity and operations
- Zero-emission truck sales and adoption
- Truck standards, technology and efficiency gains
Global Truck Emission Statistics: Scale and Freight’s Climate Share
The IEA’s 2017 baseline placed road freight at more than one-third of transport-related global CO2 emissions and 7% of total energy-related global CO2 emissions. These are sectoral estimates, so they describe road freight rather than truck tailpipes alone. The Future of Trucks
| Measure | Period | Result |
|---|---|---|
| Road freight share of transport-related CO2 | 2017 baseline | More than one-third |
| Road freight share of total energy-related CO2 | 2017 baseline | 7% |
| Global road-sector emissions | 2024 | More than 6 Gt CO2 |
| Road-sector change | 2015–2024 | 8% higher |
The later IEA road-transport update estimated that the global road sector emitted more than 6 gigatonnes of CO2 in 2024, 8% above 2015 levels. From 2019 to 2024, road-emission growth averaged 0.2% per year; that trend includes passenger cars, vans, trucks and other road vehicles, not trucks alone. The Future of Trucks
U.S. Truck Emission Statistics: Vehicle Share, Pollutants and Exposure
EPA’s Clean Heavy-Duty Vehicles Program fact sheet reported that medium- and heavy-duty vehicles represented 23% of U.S. transportation-sector greenhouse-gas emissions while making up 10% of vehicles on U.S. roads. The category is broader than freight trucks alone, and the more than 3 million Class 6 and 7 vehicles also include school buses, delivery, refuse, dump and utility vehicles. Clean Heavy-Duty Vehicles Program
- EPA identifies NOx and PM2.5 in heavy-duty exhaust as pollutant classes linked to serious health conditions such as asthma; this is a pollutant-risk description, not a quantified causal estimate.
- An estimated 72 million people in the United States lived near truck freight routes in EPA’s 2022 rule announcement; proximity is not a count of truck-exhaust exposures. Final EPA Standards for Heavy-Duty Vehicles
EPA described the model-year-2027 heavy-duty rule as more than 80% stronger than current standards. Its 2045 health and economic figures are forecasts under the final-rule scenario, not observed post-rule outcomes:
- Up to 2,900 premature deaths avoided annually.
- 6,700 hospital admissions and emergency-department visits avoided annually.
- 18,000 childhood asthma cases avoided annually.
- 3.1 million asthma-symptom and allergic-rhinitis-symptom cases avoided annually.
- 78,000 lost workdays avoided annually and 1.1 million lost school days avoided annually.
- $29 billion in annual net benefits, in 2022 dollars.
Final EPA Standards for Heavy-Duty Vehicles
Heavy-Duty Truck Idling Emission Statistics for NOx, CO2 and Diesel
EPA’s 2001–2002 idling program measured nine Class 8 heavy-duty diesel trucks. Across those tests, the average idling rate was 144 g NOx/hour, 8,224 g CO2/hour and about 0.82 gallons of diesel/hour; these rates vary with engine speed, temperature and accessory load. Study of Exhaust Emissions from Idling Heavy Duty Diesel Trucks and Commercially Available Idle Reducing Devices
| Test condition | NOx | CO2 | Diesel use |
|---|---|---|---|
| Average across tests | 144 g/hour | 8,224 g/hour | 0.82 gal/hour |
| Low engine speed, 600–800 rpm | 114 g/hour | — | — |
| High engine speed, 1,000–1,200 rpm | 190 g/hour | — | — |
In one 2001 Freightliner comparison with air conditioning, an auxiliary power unit reduced fuel use from 0.48 to 0.23 gallons/hour, NOx from 95 to 10 g/hour and CO2 from 4,787 to 2,353 g/hour. That was a single-truck technology comparison, so accessory load and test conditions matter. EPA idling study
EPA also presented an illustrative fleet scenario of 500,000 trucks idling 8 hours per day for 300 days per year. The derived scenario consumed 960 million gallons of diesel, produced 10.9 million short tons of CO2 and produced 190,476 short tons of NOx annually; these are calculations from stated assumptions, not observed national totals. EPA idling study
EU Truck Emission Statistics: Intensity, Fleet Size and Daily Distance
Trucks and buses accounted for 6% of total EU emissions in the 2024 State of European Transport report. The EU and UK had 7,159,038 trucks in 2021, while EU and UK tractor-trailers covered an average 530 km per day; the fleet count and operating distance do not directly measure emissions per truck. State of European Transport 2024: Trucks & Buses
The same source estimated total truck-and-bus emissions in the EU and UK at 240 MtCO2e in 2022. Because trucks and buses are combined, this is not a truck-only total. State of European Transport 2024: Trucks & Buses
For new trucks covered by EU CO2 standards, ICCT certification data showed average fleet-specific emissions falling from 52.5 to 52.0 gCO2 per tonne-km between 2019 and 2020. The required annual reduction to meet the EU 2025 truck CO2 target was 2.5%, a trajectory rather than an observed reduction rate. CO2 emissions from trucks in the European Union
- MAN recorded the greatest manufacturer improvement in the 2019–2020 ICCT analysis, reducing emissions by 2.7%.
- For EU vehicle group 5-LH 4×2 tractor-trailers, the spread between the 5th and 95th percentile was 18.8% in 2019 and 17.5% in 2020.
- Vehicle group 5-LH 4×2 tractor-trailers were responsible for over half of EU heavy-duty vehicle emissions in the 2020 reporting analysis.
These ICCT figures are certification-data and vehicle-group results for regulated new trucks, not measurements of the entire in-use truck fleet. ICCT truck CO2 analysis
Zero-Emission Truck Sales Statistics and Market Adoption Trends
ICCT’s 2023 EU-27 market monitor recorded 2,600 zero-emission heavy trucks above 12 tonnes, equal to 0.9% of all new heavy-truck sales. Sales rose from 820 in 2022, while the share increased from 0.3%; these are new-sales measures, not the in-use fleet or avoided emissions. Race to Zero: European heavy-duty vehicle market development
| EU-27 zero-emission heavy-truck measure | 2022 | 2023 |
|---|---|---|
| Sales | 820 | 2,600 |
| Share of new heavy-truck sales | 0.3% | 0.9% |
Germany accounted for 29% and France 21% of EU-27 zero-emission heavy-truck sales in 2023. Volvo Trucks held 42% of those sales and Renault Trucks 24%; these are country and manufacturer shares within zero-emission heavy-truck sales, not total truck sales. ICCT market development report
In Q4 2023, 920 of 86,000 EU heavy-truck sales were zero-emission, a 1.4% quarterly share. The separate light- and medium-truck segment, covering 3.5–12 tonnes, rose from 1,000 zero-emission sales in 2022 to 3,100 in 2023, and its share increased from 2.1% to 4.8%; the Ford Otosan E-Transit represented 60% of that segment’s zero-emission sales in 2023. ICCT market development report
Truck Emission Standards, Technology Targets and Efficiency Gains
DOE’s SuperTruck programs show the difference between demonstration performance and fleet averages. SuperTruck 1, conducted from 2009 to 2016, demonstrated a 50% increase in Class 8 freight efficiency and a 20% increase in engine efficiency, while more than 20 technologies were commercialized. FOTW #1346: US DOE SuperTruck 3 Initiative
SuperTruck 2, conducted from 2016 to 2023, reported these demonstration results:
- All teams achieved more than 100% improvement in freight efficiency measured in ton-mpg.
- Some teams demonstrated more than 16 miles per gallon of diesel fuel.
- All teams demonstrated more than 52% engine brake thermal efficiency.
- Three teams demonstrated pathways to 55% brake thermal efficiency.
These are team-level demonstrations against program baselines, not typical production-truck fuel economy or lifecycle emissions. DOE SuperTruck 3 Initiative
SuperTruck 3 set a 75% reduction goal for medium- and heavy-truck greenhouse-gas and air-pollution emissions on a lifecycle basis during its 2023–2027 program. That is a program goal, and its lifecycle boundary includes more than tailpipe emissions. DOE SuperTruck 3 Initiative