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Transport Emissions

Air pollutants from road transport

The air pollutant emissions from transport are a significant contribution to the overall state of air quality in Europe. Emissions of particulate matter (PM), nitrogen oxides (NO and NO2, when measured combined, they are referred to as NOx), un-burnt hydrocarbons (HC) and carbon monoxide (CO) are pollutants regulated by "Euro emissions standards".

In general, emission regulations are adopted as part of the EU framework for the type approval of cars, vans trucks, buses and coaches. Current standards are: for light duty vehicles (cars and vans) Euro 6, while the current standard for heavy duty vehicles is Euro VI.

  • Directive 2007/46/EC provides a common legal framework for the type approval of cars, vans, trucks, buses and coaches
  • Euro 5 and 6 Regulation 715/2007/EC sets the emission limits for cars for regulated pollutants, in particular nitrogen oxides (NOx, i.e. the combined emissions of NO and NO2) of 80mg/km
  • Regulation 692/2008/EC implements and amends Regulation (EC) No 715/2007 on type-approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) and on access to vehicle repair and maintenance information
  • Regulation (EU) 2016/427 of 10 March 2016 amends Regulation (EC) No 692/2008 as regards emissions from light passenger and commercial vehicles (Euro 6)
  • Regulation 595/2009/EC requires new heavy duty vehicles and engines to comply with new emission limits and introduces additional requirements on access to information.
  • Commission Regulation (EU) 582/2011 implements and amends Regulation (EC) No 595/2009 with respect to emissions from heavy duty vehicles (Euro VI).

Specifically for various pollutants, successive emission standards have led to significant drops in emissions of exhaust PM and other pollutants such as HC and CO. Here it must be stated that vehicle emission standards only cover exhaust PM emissions and PM originating from vehicles tire and break wear are currently not part of vehicle regulations. On the other hand, the transport sector is the largest contributor to NOx emissions, accounting for 46% of total emissions in 2013 in the European Union.

However, NOx emissions, and in particular NO2 emissions, from road transport have not been reduced as much as expected with the introduction of the vehicle emissions standards (the so called Euro standards) since 1991, since emissions in real-life driving conditions are often higher than those measured during the approval test (in particular for diesel vehicles). It should be noted that urban hotspots of high NO2 concentrations are even more impacted by vehicle emissions, with transport share rising to more than 60%.

Instances of possible use of defeat devices that have led to high road transport emissions are covered by existing legislation (715/2007/EC) and should be investigated and actions taken by national type-approval authorities – see also the related Commission statement.

To deal with high on-road emissions from passenger vehicles, where a significant discrepancy with the laboratory testing has been confirmed in recent years, the Commission is introducing the Real Driving Emissions test procedure (RDE) starting from 1 September 2017, which will better reflect the actual emissions on the road and reduce the current discrepancy between emissions measured in real driving to those measured in a laboratory.

The RDE procedure complements the current laboratory based procedure to check that the vehicle emission levels of nitrogen oxides (NOx), and in a next stage also particle numbers (PN), measured during the laboratory test, are confirmed in real driving conditions.

The RDE procedure has been, for practical reasons, split into several packages. The 1st RDE package was voted positively by the Member States in the Technical Committee of Motor Vehicles (TCMV) in May 2015 and has entered into force since (OJ L 82, 31.3.2016). In the RDE procedure, pollutant emissions will be measured by portable emission measuring systems (PEMS) that will be attached to the car while driving in real conditions on road. This means that the car will be driven outside and on a real road according to random acceleration and deceleration patterns. This package deals with the technical requirements for PEMS testing. In an initial phase that started in 2016 the RDE testing will only be done for monitoring purposes, without an impact on the actual type approval which will continue to be delivered on the basis of the laboratory measurements. On 28 October 2015, Member States meeting in the Technical Committee of Motor Vehicles (TCMV) voted by a large majority for the 2nd RDE package which was necessary for the RDE tests to have an actual impact on type approvals issued by national authorities. From 1 September 2017 the new RDE tests will determine whether a new car model is allowed to be put on the market. From 1 September 2019 then, a conformity factor is set at 2.1 for all new vehicles. A second stage conformity factor is equal to 1.0, with a margin parameter that takes into account the additional measurement uncertainties introduced by the PEMS equipment. The margin parameter is currently set at 0.5. The latter is subject to an annual review and shall be revised as a result of the improved quality of the PEMS procedure or technical progress.

The 3rd RDE package will define a procedure for the measurement of the particulates and include the effect of vehicle cold starts into the RDE testing. In addition the Commission will oblige manufacturers to publish the conformity factor of an individual vehicle in its certificate of conformity (CoC). In this way the consumer will have full transparency on the real emission performance.

In the 4th RDE package the Commission will define the rules for independent RDE testing of vehicles being in-service, including the regulatory consequences in case of non-conformity.

Euro VI standard for heavy duty vehicles, which is applicable now, has shown much improved pollutants emission performance in real life driving.

In addition to substantial modification of the testing regime, the Commission has tabled an ambitious proposal for reform of the European Type Approval process, which will enable effective independent market surveillance of environmental performance of vehicles.

Finally it needs to be underlined, that even if vehicle emissions standards are a very powerful tool to reduce air pollution from road vehicles, they are not the only tool available to Member States for meeting air quality objectives. Additional measures which address traffic volumes, the fuels used and/or driving behaviour are also necessary and available to Member States to implement.