1.A.3.b - Transport: Road Transport

Short description

In category 1.A.3.b - Road Transport emissions from fuel combustion activities as well as abrasive and fugitive emissions are reported within the following categories:

Abbreviations used below as well as in the following chapters on road transport for the different types of vehicles:

  • PCs - Passenger Cars
  • LDVs - Light Duty Vehicles
  • HDVs - Heavy Duty Vehicles (if not reported separatly: including buses)
  • MCs - Motorcycles (if not reported separatly: including mopeds)

Emissions from motorised road traffic in Germany are reported under this category. It includes traffic on public roads within Germany, except for agricultural and forestry transports and military transports. Calculations are made for the vehicle categories of passenger cars, motorcycles, light duty vehicles, heavy duty vehicles and buses. For calculation purposes, the vehicle categories are broken down into so-called vehicle layers with the same emissions behaviour. To this end, vehicle categories are also broken down by type of fuel used, vehicle size (trucks and buses by weight class; automobiles and motorcycles by engine displacement) and pollution control equipment used, as defined by EU directives for emissions control (“EURO norms”), and by regional traffic distribution (outside of cities, in cities and autobahn).

Since 1990, emissions of NOx, CO, NMVOC and SO2 from road transports have decreased sharply, due to catalytic-converter use and engine improvements resulting from continual tightening of emissions laws, and due to improved fuel quality.

For buses and heavy duty vehicles (over 3.5 t total permissible vehicle weight), maximum permissible levels of hydrocarbon (HC, incl. NMVOC) emissions were lowered especially sharply (-40%) via the introduction of the EURO3 standard in 2000. Since EURO3 vehicles were very quick to reach the market as of 2000, the emission factor for hydrocarbon emissions from diesel fuel - and the relevant emissions themselves – decreased considerably after 2000.

Methodology

Emissions are calculated with the aid of the TREMOD model (“Transport Emission Estimation Model” v6.02) from (Knörr, W. et al. (2020a)) 1).

This model adopts a “bottom-up” (tier3) approach whereby mileage of the individual vehicle layers is multiplied by region-specific emission factors. For passenger cars and light duty vehicles, a “cold start surplus” is also added. The total consumption calculated on the basis of fuel type is compared with the consumption according to the Energy Balance. The emissions are then corrected with the aid of factors obtained from this comparison process. For petrol-powered vehicles, the evaporation emissions of VOC are calculated in keeping with the pollution-control technology used. From the emissions and fuel consumption for the various vehicle layers, aggregated, fuelbased emission factors (kg of emissions per TJ of fuel consumption) are derived, and then the emission factors are forwarded to the CSE via a relevant interface. In keeping with the CORINAIR report structure, these factors are differentiated only by type of fuel, type of road (autobahn, rural road, city road) and, within the vehicle categories, by “without/with emissions-control equipment”. The following emissions-control categories are differentiated:

For calculation with TREMOD, extensive basic data from generally accessible statistics and special surveys were used, co-ordinated, and supplemented. An overview of the principal sources and key assumptions is given below. Detailed descriptions of the databases, including information on the sources used, and the calculation methods used in TREMOD, are provided in the aforementioned IFEU report.

Activity Data

The basis for CSE data collection for the road-transport sector consists of fuel consumption data provided by the Working Group on Energy Balances (AGEB) 2). For each year, the sum of the activity rates for the various individual structural elements must correspond to the Energy Balance data, in terajoule. The relevant basic Energy Balance data is shown in the table below.

Table 1: Fuel consumption in German road transport, in terajoules

Gasoline Diesel oil Biofuels CNG, LPG & LNG Petroleum Lubricant
1990 1.330.479 735.920 0 138 0 2.495
1991 1.332.285 785.174 0 137 0 1.668
1992 1.344.129 853.502 0 229 0 1.275
1993 1.350.617 907.787 0 184 473 857
1994 1.276.637 932.060 0 184 559 586
1995 1.299.982 964.013 1.504 138 610 447
1996 1.299.879 964.580 2.046 115 638 365
1997 1.297.487 979.586 3.652 106 357 261
1998 1.300.463 1.022.794 4.081 106 637 202
1999 1.300.602 1.097.036 5.370 100 637 113
2000 1.237.055 1.108.105 12.276 94 414 81
2001 1.199.318 1.097.416 16.740 98 471 73
2002 1.166.381 1.105.842 20.460 607 472 75
2003 1.108.989 1.078.352 29.948 694 0 71
2004 1.072.720 1.110.931 40.042 1.887 0 73
2005 992.377 1.078.620 78.897 5.484 0 77
2006 930.834 1.082.042 143.881 9.051 0 76
2007 892.982 1.073.987 155.752 14.787 0 79
2008 854.002 1.102.624 126.181 22.796 0 80
2009 829.227 1.114.939 113.765 32.285 0 86
2010 791.416 1.168.063 120.129 30.591 0 81
2011 787.803 1.197.252 115.828 32.384 0 80
2012 742.000 1.223.718 120.513 32.438 0 76
2013 741.150 1.283.637 109.358 30.508 0 77
2014 744.661 1.296.828 113.957 28.983 0 77
2015 708.672 1.348.789 105.764 26.420 0 77
2016 709.179 1.393.481 106.054 22.705 0 77
2017 719.580 1.425.424 108.049 20.667 0 77
2018 692.694 1.377.104 112.594 21.514 0 80
2019 699.936 1.392.585 111.857 23.233 0 82

Source: Evaluation tables of the Energy Balances, “Mineralölzahlen” (“Petroleum Data”) of the Association of the German Petroleum Industry (MWV) 3) and “Amtliche Mineralöldaten” (“Official Petroleum Data”, BAFA); lubricant in 2-Stroke mix: TREMOD

For more information on the derivation of activity data and the emission factors applied, please refer to the sub-ordinate chapters as well as Appendix 2.2.

Uncertainties

Uncertainty estimates for activity data of mobile sources derive from research project FKZ 360 16 023: “Ermittlung der Unsicherheiten der mit den Modellen TREMOD und TREMOD-MM berechneten Luftschadstoffemissionen des landgebundenen Verkehrs in Deutschland” by (Knörr et al. (2009)) 4).

Uncertainty estimates for emission factors for all 1.A.3.b sub-categories were compiled during the PAREST research project. Here, the final report has not yet been published.

Recalculations

Due to the revision of the underlying TREMOD model, several country-specific emission factors have been revised fundamentally for the entire time series as of 1990. For more details please refer to chapter 1.A.3.b i-iv - Emissions from Fuel Combustion in Road Vehicles.

Planned improvements

Besides the routine revision of the TREMOD model, no specific improvements are planned.


1) Knörr et al. (20120a): Knörr, W., Heidt, C., Gores, S., & Bergk, F.: Fortschreibung des Daten- und Rechenmodells: Energieverbrauch und Schadstoffemissionen des motorisierten Verkehrs in Deutschland 1960-2035, sowie TREMOD, im Auftrag des Umweltbundesamtes, Heidelberg [u.a.]: Ifeu Institut für Energie- und Umweltforschung Heidelberg GmbH, Heidelberg & Berlin, 2020.
2) AGEB (2020): Working Group on Energy Balances (Arbeitsgemeinschaft Energiebilanzen (Hrsg.), AGEB): Energiebilanz für die Bundesrepublik Deutschland; URL: https://ag-energiebilanzen.de/7-0-Bilanzen-1990-2018.html, Köln & Berlin, 2020.
3) MWV (2020): Association of the German Petroleum Industry (Mineralölwirtschaftsverband, MWV): Annual Report 2018, page 65, Table 'Sektoraler Verbrauch von Dieselkraftstoff 2012-2018'; URL: https://www.mwv.de/wp-content/uploads/2020/09/MWV_Mineraloelwirtschaftsverband-e.V.-Jahresbericht-2020-Webversion.pdf, Berlin, 2020.
4) Knörr et al. (2009): Knörr, W., Heldstab, J., & Kasser, F.: Ermittlung der Unsicherheiten der mit den Modellen TREMOD und TREMOD-MM berechneten Luftschadstoffemissionen des landgebundenen Verkehrs in Deutschland; final report; URL: https://www.umweltbundesamt.de/sites/default/files/medien/461/publikationen/3937.pdf, FKZ 360 16 023, Heidelberg & Zürich, 2009.